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Ms. B. B. Vaghasia, Assistant Professor, Page 1 Faculty of Pharmacy, Dr. Subhash Technical Campus, Junagadh
SEMESTER IV
PHARMACEUTICAL ORGANIC
CHEMISTRY - III
(BP401TT)
Multiple Choice Questions
(Chapter 1 & 2 – Stereochemistry)
(Chapter 3 – Heterocyclic compound – I)
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1) 1 Hexane and 3-methylpentane are examples of:
a. Enantiomers.
b. Stereoisomer.
c. Diastereomers.
d. Constitutional isomers.
Ans. – d
2) Cis-trans isomers are:
a. Diastereomers.
b. Enantiomers.
c. Geometric isomers.
d. Constitutional isomers.
Ans. – c
3) (2R,4S) –2,4–Dichloropentane and (2S,4R)-2,4-dichloropentane are:
a. Enantiomers
b. Diastereomers
c. identical
d. conformational isomers
Ans. – c
4) Which of the following molecules is achiral?
a. (2R,3R)-2,3-Dichloropentane
b. (2R,3S)-2,3-Dichloropentane
c. (2S,4S)-2,4-Dichloropentane
d. (2S,4R)-2,4-Dichloropentane
Ans. – d
5) Which statement is not true for a meso compound?
a. The specific rotation is 0º.
b. There are one or more planes of symmetry.
c. More than one stereogenic center must be present.
d. The stereo chemical labels, (R) and (S), must be identical for each stereogenic centre.
Ans. – d
6) Which is a meso compound?
a. (2R,3R)-2,3-Dibromobutane
b. (2R,3S)-2,3-Dibromopentane
c. (2R,4R)-2,4-Dibromopentane
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d. (2R,4S)-2,4-Dibromopentane
Ans.- d
7) What is the percent composition of a mixture of (S)-(+)-2-butanol,[!] D/25 = +13.52º,
and (R)-(-)-2-butanol,[!] D/25 = -13.52º, with a specific rotation [!] D/25 = +6.76º?
a. 75%(R) 25%(S)
b. 25%(R) 75%(S)
c. 50%(R) 50%(S)
d. 67%(R) 33%(S)
Ans. – b
8) Which one of the following can exist in optically active forms?
a. cis-1,3-Dichlorocyclohexane
b. trans-1,3-Dichlorocyclohexane
c. cis-1,4-Dichlorocyclohexane
d. trans-1,4-Dichlorocyclohexane
Ans. – b
9) Which of these is a comparatively insignificant factor affecting the magnitude of
Specific optical rotation?
a. Concentration of the substance of interest
b. Purity of the sample
c. Temperature of the measurement
d. Length of the sample tube
Ans. – c
10) What can be said with certainty if a compound has [!] D/25 = -9.25º ?
a. The compound has the (S) configuration.
b. The compound has the (R) configuration.
c. The compound is not a meso form.
d. The compound possesses only one stereogenic center.
Ans. – c
11) An alkane which can exhibit optical activity is:
a. Neopentane
b. Isopentane
c. 3–Methylpentane
d. 3–Methylhexane
Ans. – d
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12) In the absence of specific data, it can only be said that (R)–2–bromopentane is:
a. Dextrorotatory (+).
b. Levorotatory (–).
c. Optically inactive.
d. Chiral.
Ans. – d
13) If a solution of a compound (30.0 g/100 mL of solution) has a measured rotation of +15º in a 2 dm
tube, the specific rotation is:
a. +50º
b. +25º
c. +15º
d. +7.5º
Ans. – b
14) Which compound would show optical activity?
a. cis 1,4- Dimethylcyclohexane
b. trans 1,4- Dimethylcyclohexane
c. cis 1,4- Dimethylcycloheptane
d. trans 1,4- Dimethylcycloheptane
Ans. – d
15) Of the compounds which correspond to the general name "dichlorocyclobutane", how many are
optically active?
a. 0
b. 1
c. 2
d. 3
Ans. – c
16) Which of the following is true of any (S)-enantiomer?
a. It rotates plane-polarized light to the right.
b. It rotates plane-polarized light to the left.
c. It is a racemic form.
d. It is the mirror image of the corresponding (R)-enantiomer.
Ans. – d
17) Enantiomers are:
a. Molecules that have a mirror image.
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b. Molecules that have at least one stereogenic center.
c. Non-superposable molecules.
d. Non-superposable molecules that are mirror images of each other.
Ans. – d
18) Which of the following is NOT true of enantiomers? They have the same:
a. Boiling point.
b. Melting point.
c. Specific rotation.
d. Density.
Ans. – c
19) Which statement is true of 1,3-dimethylcyclobutane?.
a. Only one form of the compound is possible.
b. Two diastereomeric forms are possible.
c. Two sets of Enantiomers are possible.
d. Two enantiomeric forms and one meso comp.
Ans. – b
20) CH3CHBrCH2CHClCH3 is the generalized representation of what number of stereo isomers?
a. 3
b. 4
c. 5
d. 6
Ans. – b
21) For the generalized structure BrCH2CHClCH2CHClCH2Br there exists what number of
stereoisomers?
a. 2
b. 3
c. 4
d. 6
Ans. – c
22) How many discrete dimethylcyclopropanes are there?
a. 2
b. 3
c. 4
d. 5
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Ans. – c
23) What is the molecular formula for the alkenes of smallest molecular weight which possesses a
stereogenic center?
a. C4H10
b. C5H12
c. C6H14
d. C7H16
Ans. – d
24) How many chiral stereoisomers can be drawn for CH3CHFCHFCH (CH3)2?
a. 1
b. 2
c. 3
d. 4
Ans. – d
25) How many different compounds are there which correspond to the general name "3-(1-
methylbutyl) cyclobutanol”?
a. 2
b. 4
c. 6
d. 8
Ans. – b
26) Which of the statements below correctly describes an achiral molecule?
a. The molecule has a nonsuperimposable mirror image.
b. The molecule exhibits optical activity when it interacts with plane-polarized light.
c. The molecule has an enantiomer.
d. The molecule might be a meso form.
Ans. – d
27) Which of the following statements correctly pertains to a pair of enantiomers?
a. They rotate the plane of polarized light by exactly the same amount and in opposite
directions.
b. They rotate the plane of polarized light by differing amounts and in opposite directions.
c. They rotate the plane of polarized light by differing amounts and in the same direction.
d. They have different melting points.
Ans. – a
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28) A mixture of equal amounts of two enantiomers __________.
a. is called a racemic mixture
b. is optically inactive
c. implies that the enantiomers are meso forms
d. both A and B
Ans. – d
29) __________ is the use of an optically active reagent or catalyst to convert an optically inactive
starting material into an optically active product.
a. Asymmetric induction
b. Racemization
c. Optical reduction
d. Meso effection
Ans. – a
30) Which of the following statements is (are) true for the compound (R)-2-butanol?
a. This compound is chiral.
b. This compound is optically active.
c. This compound has an enantiomer.
d. all of the above
Ans. – d
31) Which of the following statements is (are) true for the compound (3R, 4R)-3,4-dimethylhexane?
a. This compound is chiral.
b. The enantiomer of this compound is (3S, 4S)-3,4-dimethylhexane.
c. This compound is a diastereomer of (3R, 4S)-3,4-dimethylhexane.
d. all of the above
Ans. – d
32) Which of the following statements is (are) true for the compound cis-1,2-dichlorocyclopropane?
a. This compound is chiral.
b. The enantiomer of this compound is trans-1,2-dichlorocyclopropane.
c. This compound contains no asymmetric carbons.
d. none of the above
Ans. – d
33) How many asymmetric carbon atoms are present in the following compound?
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a. 0
b. 1
c. 2
d. 3
Ans. – b
34) How many chiral carbon atoms are present in the following compound?
a. 0
b. 1
c. 2
d. 3
Ans. – a
35) Which of the following terms correctly describe(s) the structural relationship between cis-1,3-
dimethylcyclopentane and trans-1,3-dimethylcyclopentane?
a. enantiomers
b. diastereomers
c. geometric isomers
d. both B and C
Ans. – d
36) How many diastereomers are there of the molecule shown below?
a. 0
b. 2
c. 4
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d. 6
Ans. – d
37) How many enantiomers are there of the molecule shown below?
a. 0
b. 2
c. 4
d. 6
Ans. – a
38) What term describes the structural relationship between (E)- and (Z)-2-pentene?
a. Constitutional isomers
b. Enantiomers
c. Geometric isomers
d. Conformers
Ans. – c
39) Compounds which have different arrangements of atoms in space while having same atoms
bonded to each other are said to have
a. position isomerism
b. functional group isomerism
c. chain isomerism
d. stereoisomerism
Ans. – d
40) Which of the following can make difference in optical isomers?
a. heat
b. temperature
c. polarized light
d. pressure
Ans. – c
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41) Which of the following terms best describes the following pair of molecules?
a. Isomers
b. Constitutional isomers
c. Configurational isomers
d. Geometrical isomers
Ans. – d
42) What is the relationship between the two groups in the following molecules?
a. They are equatorial to one another
b. They are axial to one another
c. They are cis to one another
d. They are trans to one another
Ans. – c
. 43) What is the stereochemical relationship between the following two molecules?
a. Geometrical isomers
b. Enantiomers
c. Diastereomers
d. Identical
Ans. – d
44) Which of the following is an alkane which can exhibit optical activity?
a. Neopentane
b. Isopentane
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c. 3–Methylpentane
d. 3–Methylhexane
Ans. – d
45) Hexane and 3-methylpentane are examples of:
a. enantiomers.
b. stereoisomers.
c. diastereomers.
d. constitutional isomers.
Ans. – d
46) Which of these is a comparatively insignificant factor affecting the magnitude of specific optical
rotation.
a. Concentration of substance of interest
b. Temperature of measurement
c. Length of the sample tube
d. All of the above
Ans. – d
47) How many chiral stereoisomers can be drawn for CH3CHFCHFCH(CH3)2?
a. 2
b. 4
c. 6
d. 8
Ans. – b
48) How many different compounds are there which correspond to the general name "3-(1-
methylbutyl)cyclobutanol”?
a. 2
b. 4
c. 6
d. 8
Ans. – b
49) Which of the following is NOT true of enantiomers? They have the same:
a. boiling point.
b. melting point.
c. specific rotation.
d. chemical reactivity toward achiral reagents.
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Ans. – d
50) Which statement is true for 1,3-dimethylcyclobutane?
a. Only one form of the compound is possible
b. Two diastereomeric forms are possible.
c. Two enantiomeric forms and one meso compound are possible.
d. None of the above.
Ans. – b
51) Which of the following is true of any (S)-enantiomer?
a. It rotates plane-polarized light to the right.
b. It rotates plane-polarized light to the left.
c. It is a racemic form.
d. It is the mirror image of the corresponding (R)-enantiomer.
Ans. – d
52) If a solution of a compound (30.0 g/100 mL of solution) has a measured rotation of +15º
in a 2 dm tube, the specific rotation is:
a. +50º
b. +25º
c. +15º
d. +7.5º
Ans. – b
53) In the absence of specific data, it can only be said that (R)–2–bromopentane is:
a. dextrorotatory (+).
b. levorotatory (–).
c. analogous in absolute configuration to (R)–2–bromopentane.
d. optically inactive.
Ans. – c
54) Which is a meso compound?
a. (2R,3R)-2,3-Dibromobutane
b. (2R,3S)-2,3-Dibromopentane
c. (2R,4R)-2,4-Dibromopentane
d. (2R,4S)-2,4-Dibromopentane
Ans. – d
55) Which is achiral from the following molecules?
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a. (2R,3R)-2,3-Dichloropentane
b. (2R,3S)-2,3-Dichloropentane
c. (2S,4S)-2,4-Dichloropentane
d. (2S,4R)-2,4-Dichloropentane
Ans. – d
56) Those stereoisomers which can be interconverted only by breaking and remaking of covalent
bonds are called as____
a. Chain isomers
b. Positional isomers
c. Configurational isomers
d. Conformational isomers
Ans. – c
57) Those stereoisomers which can be interconverted by simple rotation about sigma bonds are called
as____
a. Conformational isomers
b. Functional isomers
c. Geometric isomers
d. Tautomers
Ans. – a
58) A beam of light having a particular wavelength and having vibrations only in one plane is____
a. Ordinary light
b. Plane polarized light
c. Monochromatic light
d. None of above
Ans. – b
59) Optically active compound can rotate_____
a. Ordinary light
b. Plane polarized light
c. Monochromatic light
d. None of above
Ans. – b
60) Which instrument is used to measure angle of rotation?
a. Polarimeter
b. UV spectrometer
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c. pH meter
d. Conductometer
Ans. – a
61) For being chiral compound, chemical compound should not possess following characteristic
a. Plane of symmetry
b. Centre of symmetry
c. Axis of symmetry
d. All of the above
Ans. – d
62) Followings are types of optical isomers except__
a. Enantiomers
b. Diasteromers
c. Conformers
d. Meso compounds
Ans. – c
63) How many possible stereoisomers for the compound CH3CH(OH)COOH.
a. 1
b. 2
c. 3
d. 4
Ans. – b
64) Which is the true option for Diastereomers?
a. They have only one chiral centre.
b. They have identical physical properties
c. They have two or more chiral centre.
d. All of the above.
Ans. – c
65) Ratio of dextro and levo isomers (d:l) of compound present in raceme mixture is__
a. 50:50
b. 40:60
c. 30:70
d. 20:80
Ans. – a
66) The process of separation of a racemic mixture into optically active d and l isomers is___
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a. Racemization
b. Resolution
c. Both (a) and (b)
d. None of the above
Ans. – b
67) Absolute configuration of stereoisomer is denoted by__
a. R and S isomers
b. D and L isomers
c. d and l isomers
d. cis and trans isomers
Ans. – a
68) Relative configuration of stereoisomer is denoted by__
a. R and S isomers
b. D and L isomers
c. d and l isomers
d. cis and trans isomers
Ans. – b
69) The necessary conditions for geometric isomers are__
a. Presence of at least one double bond.
b. Each carbon atom of the double bond should be linked to two different atoms or groups.
c. Both (a) and (b)
d. None of the above.
Ans. – c
70) By studying which physical property, configuration of geometric isomers can be determined
a. Melting point
b. Solubility
c. Dipole moment
d. All of the above
Ans. – d
71) From the followings, which is true about conformational isomers?
a. Eclipsed conformation is more stable than staggered conformation.
b. Eclipsed conformation is less stable than staggered conformation.
c. Eclipsed conformation has low energy than staggered conformation.
d. None of the above
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Ans. – b
72) Most stable conformation of cyclohexane is___
a. Chair conformation
b. Boat conformation
c. Twist boat conformation
d. Half chair conformation
Ans. – a
73) The hydrogens lying in the plane of the cyclohexane ring are called____
a. Axial hydrogens
b. Chiral hydrogens
c. Equatorial hydrogens
d. None of the above
Ans. – c
74) The hydrogens lying above or below the plane of the cyclohexane ring are called____
a. Axial hydrogens
b. Chiral hydrogens
c. Equatorial hydrogens
d. None of the above
Ans. – a
75) Which is the true sentence for stereospecific reactions from the followings,
a. Reactants react at different rate i.e. they have different rate of reaction.
b. They give different stereoisomers as products.
c. They have different paths to give different types of compounds as products.
d. All of the above
Ans. – d
76) Which of the following statements most accurately describes the stereochemistry between the
various cyclohexanes?
a. Cis-1,2-dichlorocyclohexane and trans-1,2-dichlorocyclohexane rotate plane-polarized light in
opposite directions, and together in equal proportions form a racemic mixture.
b. The diaxial and diequatorial forms of trans-1,3-dichlorohexane can be separated by their
differing physical properties.
c. Only cis-1,4-dichlorocyclohexane is achiral due to a plane of symmetry, and cis-1,4-
dichlorocyclohexane is diastereomeric to trans-1,4-dichlorocyclohexane.
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d. The conformational isomers of trans-1,2-dichlorocyclohexane are enantiomers, which are not
interconvertible, but resolvable.
Ans. – d
77) Which of the following is a mesocompound?
a. I
b. II
c. III
d. IV
Ans. – b
78) Which of the following is(are) not meso compound(s)?
a. II
b. II and III
c. I and III
d. I and II
Ans. – d
79) Which of the following is(are) not meso compound(s)?
a. I
b. II and III
c. I and III
d. I and II
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Ans. – a
80) Which of the following is the definition of a pair of diastereomers?
a. A pair of stereoisomers each of which has two chirality centers
b. Any pair of stereoisomers
c. A pair of stereoisomers that are not mirror images of one another
d. A pair of stereoisomers that are non-superimposable mirror images of one another
Ans. – c
81) What is the relation between the given compound?
a. constitutional isomers
b. enantiomers
c. Diastereomers
d. Identical
Ans. – c
82) What is the relation between the given compounds?
a. Diastereomers
b. constitutional isomers
c. enantiomers
d. identical
Ans. – a
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83) What is the relation between the given compounds?
a. Diastereomers
b. constitutional isomers
c. enantiomers
d. identical
Ans. – a
84) Which of the following statements regarding enantiomers not true?
a. All (+) enantiomers are levorotatory
b. All (-) enantiomers rotate plane polarized light in a clockwise direction
c. (+) and (-) enantiomers rotate plane polarized light in opposite directions
d. All R enantiomers are dextrorotatory
Ans. – c
85) Which of the following is/are the S-enantiomer of alanine?
a. Only 1
b. Only 2
c. 1 and 3
d. 2 and 3
Ans. – c
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86) Which of the following is the pair of enantiomer from the following substance?
a. I and II
b. II and III
c. III and IV
d. I and V
Ans. – a
87) Which of the following is capable of existing as a pair of enantiomers?
a. 2-methylpropane
b. 2-methylpentane
c. 3-methylpentane
d. 3-methylhexane
Ans. – d
88) Which statement about a chiral compound A is incorrect?
a. A racemate contains equal amounts of (+)-A and (–)-A
b. If A is resolved, it is separated into its enantiomers
c. (+)-A can also be labelled R-A, because (+) means the same as R
d. (+)-A and (–)-A will rotate polarized light equally but in opposite directions
Ans. – d
89) Which of the following is the definition of chirality?
a. The superimposability of an object on its mirror image
b. A molecule with a mirror image
c. The non-superimposability an object on its mirror image
d. A molecule that has a carbon atom with four different substituents
Ans. – d
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90) Which of the following compound(s) is/are chiral?
a. Both A and B
b. Only B
c. Only A
d. Neither A nor B
Ans. – a
91) Which symmetry element makes the given compound achiral?
a. Plane of symmetry (POS)
b. Center of symmetry (COS)
c. Axis of symmetry (AOS)
d. Alternating axis of symmetry (AAOS)
Ans. – a
92) Which of the following is the definition for enatiomerism?
a. A pair of stereoisomers each of which has two chirality centres
b. A pair of stereoisomers that are not mirror images of one another
c. A pair of stereoisomers that are non-superimposable mirror images of one another
d. Any pair of stereoisomers
Ans. – c
93) Which of the following notations is not used to distinguish between pairs of enantiomers?
a. R and S
b. E and Z
c. + and –
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d. D and L
Ans. – b
94) Which among the following is not true about enantiomerism?
a. Assignments of R and S labels and (+) and (–) labels are not connected
b. The labels R and S refer to different conformers
c. The labels (+) and (–) are used to distinguish enantiomers
d. The specific rotation of enantiomers is equal and opposite
Ans. – b
95) Which of the following molecules does not possess enantiomers?
a. CH3CH2CH2CHBrCH3
b. CH3CH2CBr2CH3
c. CH3CHBrCH2CH3
d. CHBr2CH2CHBrCH3
Ans. – b
96) What does a polarimeter measure?
a. Polarity of the substance
b. Angle of rotation of an optical active compound
c. Concentration of the substance
d. pH of the substance
Ans. – b
97) A solution of 0.1 g/mL of a pure R enantiomer in a 1.0 dm (i.e., 10 cm) polarimeter rotates plane
polarized light by +4.8°. What is the rotation observed on this solution in a 2 dm polarimeter?
a. +2.4°
b. +4.8°
c. +19°
d. +9.6°
Ans. – d
98) . Polarimeter works on the principle of which of the following?
a. polarization of light
b. change of the electrical conductivity of solution with composition
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c. change of angle of refraction with composition
d. change of electrical conductivity of solution with temperature
Ans. – a
99) Which of the following groups has the highest priority according to the Cahn-Ingold-Prelog
sequence rules?
a. CH3
b. CH2Cl
c. CH2OH
d. CHO
Ans. – d
100) What is the percent composition of a mixture of (S)-(+)-2-butanol, α= +13.52°, and (R)-(-
)-2-butanol, α = -13.52°, with a specific rotation α = +6.76°?
a. 75%(R) 25%(S)
b. 25%(R) 75%(S)
c. 50%(R) 50%(S)
d. 67%(R) 33%(S)
Ans. – a
101) What can be said with certainty if a compound has α= -9.25°?
a. The compound has the (S) configuration
b. The compound has the (R) configuration
c. The compound is not a meso form
d. The compound possesses only one stereogenic center
Ans. – c
102) Which of the following compounds can exhibit geometrical isomerism?
a. 1-Hexene
b. 2-Methyl-2-Pentene
c. 3-methyl-1-pentene
d. 2-Hexene
Ans. – d
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103) How many stereoisomers are there for the following structure?
a. 1
b. 2
c. 3
d. 4
Ans. – c
104) How many stereoisomers of 3-bromo-2-butanol, CH3CH(OH)CHBrCH3, exist?
a. 3
b. 1
c. 2
d. 4
Ans. – d
105) How many stereoisomers of 2,3-butanediol, CH3CH(OH)CH(OH)CH3, exist?
a. 3
b. 4
c. 1
d. 2
Ans. – a
106) How many number of stereoisomers possible for 2, 3-pentanediol?
a. 3
b. 4
c. 5
d. 6
Ans. – b
107) Which of the following is a not a five membered ring?
a. Pyridine
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b. Pyrrole
c. Furan
d. Thiophene
Ans. – a
108) Which of the following five membered a ring is most resonance stabilized?
a. Furan
b. Thiophene
c. Pyrrole
d. Pyridine
Ans. – b
109) Five membered rings come under which category of heterocycle classification on the basis
of chemical behavior?
a. -excessive heterocycle
b. -deficient heterocycle
c. -equivalent heterocycle
d. Can’t say about the five membered rings
Ans. – a
110) Which is the most reactive five membered heterocyclic compound?
a. Pyrrole
b. Furan
c. Thiophene
d. Pyridine
Ans. – a
111) What is the product when thiophene reacts with Br2 in benzene?
a. 2-bromothiophene
b. 3-bromothiophene
c. 2,5-dibromothiophene
d. 3,4-dibromothiophene
Ans. – c
112) What is the product when pyrrole reacts with Br2 in ethanol?
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a. 2,3-dibromopyrrole
b. 2,3,4,5-tetrabromopyrrole
c. 2,5-dibromopyrrole
d. 3,4-dibromopyrrole
Ans. – b
113) What is the name of the following reaction?
a. Gattermann reaction
b. Riemer tiemann reaction
c. Friedal craft reaction
d. Blanc’s chloromethylation
Ans. – b
114) What is the name of the following reaction?
a. Gattermann reaction
b. Riemer tiemann reaction
c. Friedal craft reaction
d. Blanc’s chloromethylation
Ans. – a
115) What will be the reagent used for the completion of the following reaction?
a. Concentrated acid
b. Dilute acid
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c. Concentrated base
d. Dilute base
Ans. – b
116) Which heteroatom present in pyrrole?
a. Oxygen
b. Nitrogen
c. Silicon
d. Sulphur
Ans. – b
117) Which heteroatom present in Furan?
a. Oxygen
b. Nitrogen
c. Silicon
d. Sulphur
Ans. – a
118) Which heteroatom present in thiophene?
a. Nitrogen
b. Silicon
c. Oxygen
d. Sulphur
Ans. – d
119) Which compound is most basic?
a. Pyridine
b. Pyrrole
c. Imidazole
d. Pyrrolidine
Ans. – c
120) Which is least basic compound?
a. Pyridine
b. Pyrrole
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c. Imidazole
d. Pyrrolidine
Ans. – b
121) Which of the following solvents is a heterocyclic compound?
a. DMSO
b. DMF
c. THF
d. None of the above
Ans. – c
122) Which of the followings statements is correct?
a. Pyrrole has less aromatic character than furan
b. Pyridine is isoelectronic with benzene
c. Pyridine is tertiary amine
d. Pyrrole is strong base
Ans. – c
123) What is the correct order of reactivity (most reactive first) of pyrrole, furan and thiophene
towards electrophiles?
a. Furan > Pyrrole > Thiophene
b. Pyrrole > Furan > Thiophene
c. Furan > Thiophene > Pyrrole
d. Thiophene > Pyrrole > Furan
Ans. – b
124) Electrophilic substitution in furan usually occurs at:
a. Both the C2 and C3 atom
b. The O atom
c. The C2 atom
d. The C3 atom
Ans. – c
125) Nitration of pyrrole is best carried out using:
a. Acetyl nitrate
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b. Ammonium nitrate
c. Concentrated nitric and sulphuric acid
d. Nitric acid
Ans. – a
126) If you wanted to form 2,3,4,5-tetrabromopyrrole from pyrrole, which of the following
conditions would be the best choice?
a. Br2 at 273K
b. Br2 at298 K
c. Br2 in the presence of radical initiator
d. Br2 in the presence of Lewis acid
Ans. – c
127) Which statement about thiophene is incorrect?
a. The S atom contributes two electrons to the n-system
b. Thiophene is polar
c. Thiophene is less reactive than pyrrole
d. Thiophene is more reactive than furan
Ans. – d
128) Pyrrole undergoes sulfonation in presence of _______to produce pyrrole – 2 – sulfonic
acid.
a. Conc. Sulphuric acid
b. SO3 and pyridine
c. Dilute sulphuric acid/pyridine
d. SO3 and ethanol
Ans. – b
129) Pyrrole undergoes iodination in presence of Iodine and potassium iodide to produce_____.
a. 2 – iodo pyrrole
b. 3 – iodo pyrrole
c. Tetra iodo pyrrole
d. Tri iodo pyrrole
Ans. – c
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130) Oxidation of pyrrole in presence of chromium oxide (Cr2O3) and acetic acid
produce_______.
a. Maleinimide
b. Maleic acid
c. Pyrrole N-oxide
d. None of the above
Ans. – a
131) Pyrrole is reduced by using Zn and acetic acid to get product_______
a. 2 – pyrroline
b. 3 – pyrroline
c. Pyrrolidine
d. All of the above
Ans. – b
132) Which product will be produced when pyrrole undergoes catalytic reduction in presence of
hydrogen gas and Ni metal?
a. 2 – pyrroline
b. 3 – pyrroline
c. Pyrrolidine
d. All of the above
Ans. – c
133) Identify the given heterocyclic compound.
a. Furan
b. Pyrazole
c. Pyrrole
d. Pyridine
Ans. – c
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134) Pyrrole potassium on treatment with CO2 under pressure give mixture of 2 and 3 pyrrole –
carboxylic acid, identify the reaction.
a. Kolbe-Schmidt reaction
b. Reamer-Tiemann reaction
c. Gattermann Koch reaction
d. Coupling reaction
Ans. – a
135) Pyrrole is heated with_________ to open the ring and form succinaldehyde dioxime.
a. Concentrated sulphuric acid
b. Strong alkali with pyridine
c. Hydrogen cyanide with HCl
d. Ethanolic hydroxylamine hydrochloride
Ans. – d
136) Atorvastatin, drug useful in CVS disease, contain heterocyclic ring______.
a. Pyrazole
b. Pyrrole
c. Imidazole
d. Purine
Ans. – b
137) Bepridil, calcium channel blocker, contain heterocyclic ring_____
a. Pyrrole
b. Purine
c. Indole
d. Pyridine
Ans. – a
138) Ondansetron, anti emetic drug, contain heterocyclic ring______.
a. Thiophene
b. Pyrrole
c. Furan
d. Pyrimidine
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Ans. – b
139) Which drug(s) possess pyrrole heterocyclic compound from the followings?
a. Captopril
b. Lincomycin
c. Triprolidine
d. All of the above
Ans. – d
140) Identify the following heterocyclic compound.
a. Furan
b. Thiophene
c. Oxazole
d. Thiazole
Ans. – a
141) Complete the following reaction.
a. Pyrrole
b. Furan
c. Indole
d. Oxazole
Ans. – b
142) Which would be the intermediate in the following reaction?
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a. Furan – 2 carboxide
b. Furan- 2 – carbinol
c. Furoic acid
d. None of the above
Ans. – c
143) Which would be the product when furan undergoes sulfonation in the presence of SO3 and
pyridine?
a. Furan – 2 – sulfolic acid
b. Furan – 3 – sulfonic acid
c. Mixture of (a) & (b)
d. None of the above
Ans. – a
144) Which reagent is used for the nitration of furan?
a. Conc. Nitric acid and sulphuric acid
b. Acetyl nitrate
c. Nitrobenzene
d. Dilute nitric acid with benzene
Ans. – b
145) Friedel craft acetylation of furan by using acetic anhydride is carried out in the presence of
catalyst______.
a. AlCl3
b. FeCl3
c. BF3
d. LIAlH4
Ans. – c
146) Identify the reaction: when furan react with aryl diazonium chloride in the presence of
strong alkali to produce 2 – aryl furan.
a. Mercuration
b. Gattermann Koch reaction
c. Kolbe reaction
d. Gomberg reaction
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Ans. – d
147) Bromination of furan by using Br2 will produce_________.
a. 2 – bromo furan
b. 3 – bromo furan
c. 2,5 – dibromo furan
d. None of the above
Ans. – d
148) Identify the following reaction:
a. Cannizaro reaction
b. Benzoin condensation
c. Gomberg reaction
d. Mercuration
Ans. – a
149) Identify the following reaction:
a. Gomberg reaction
b. Reamer tiemann reaction
c. Benzoin condensation
d. Aldol condensation
Ans. – c
150) Complete the reaction:
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a. Br2
b. HBr
c. KBr in alcohol
d. NaBr in pyridine
Ans. – a
151) Furan on treatment with acid undergoes protonation and form________.
a. Protonated furan
b. Polymeric product
c. Dihydro furan
d. None of the above
Ans. – b
152) Oxidation of furan produces_________.
a. Furan oxide
b. Furfural
c. Furfuric acid
d. Succinaldehyde
Ans. – d
153) Catalytic reduction of furan gives______
a. 2,3 – dihydro furan
b. 2,5 – dihydro furan
c. Tetra hydro furan
d. 3,4 – dihydro furan
Ans. – c
154) Prazocin, sympatholytic drug contain__________heterocyclic ring.
a. Furan
b. Pyrrole
c. Oxazole
d. Indole
Ans. – a
155) Which drug of following does not contain furan ring?
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a. Furazolidone
b. Lorpiprazole
c. Terazocin
d. Dantrolene
Ans. – b
156) Amiodarone, antiarrhythmic agent, possess_________ heterocyclic ring.
a. Pyridine
b. Furan
c. Thiophene
d. Purine
Ans. – b
157) From the followings, which drug contain furan heterocyclic ring?
a. Furazolidine
b. Nitrofurantoin
c. Fluticazone
d. All of the above
Ans. – d
158) Ranitidine, H2 receptor antagonist, possess________heterocyclic ring.
a. Acridine
b. Azepine
c. Pyridine
d. Furan
Ans. – d
159) Pilocarpine, cholinergic agonist, contains________heterocyclic ring.
a. Furan
b. Pyrrole
c. Thiophene
d. Purine
Ans. – a
160) Which heterocyclic ring is present in Diloxanide furoate, anti protozoal drug?
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a. Acridine
b. Thiazole
c. Furan
d. Thiophene
Ans. – c
161) Which heterocyclic ring is present in Rofecoxib, NSAID?
a. Pyrrole
b. Furan
c. Purine
d. Indole
Ans. – b
162) Which is the following heterocyclic compound?
a. Thiophene
b. Thiazole
c. Furan
d. Pyrrole
Ans. – a
163) Complete the reaction:
a. Thiazole
b. Oxazole
c. Thiphene
d. Furan
Ans. – c
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164) What would be the product of following reaction?
a. Thiophene
b. Thiazole
c. Purine
d. Pyrimidine
Ans. – a
165) What would be the appropriate reaction condition for the following reaction;
a. SO2/AlCl3/673K
b. H2S/AlCl3/273K
c. H2S/Al2O3/673K
d. Sulphur/heat
Ans. – c
166) What is not true about thiophene from the following sentences?
a. Thiophene shows aromaticity.
b. Thiophene contains oxygen heteroatom.
c. Thiophene has diene like structure.
d. Thiophene has a flat pentagonal ring.
Ans. – b
167) Which is the true statement from followings?
a. Thiophene is more stable than pyrrole
b. Thiophene is more stable than furan
c. Both (a) & (b)
d. None of the above
Ans. – c
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168) Thiophene shows electrophilic substitution reactions mainly at position___.
a. C2
b. C3
c. C4
d. C5
Ans. – a
169) Which condition is appropriate for the nitration of thiophene?
a. Acetyl nitrate
b. Nitric acid +acetic anhydride
c. Concentrated nitric acid
d. Sodium nitrate
Ans. – b
170) Identify the reaction: When thiophene react with dimethyl formamide in the presence of
POCl3, it will produce thiophene – 2 – carboxaldehyde.
a. Kolbe reaction
b. Canizzaro reaction
c. Gattermann Koch reaction
d. Vilsmeir – Hoack reaction
Ans. – d
171) Sulfonation of thiophene can be carried out by using______________.
a. SO3 +Conc. HCl
b. Dilute Sulphuric acid
c. Concentrated Sulphuric acid
d. SO3 + HNO3
Ans. – c
172) Chloromethylation of thiophene is carried out with HCHO & HCl, it will
produce_______.
a. 2- chloromethyl thiophene
b. 2- methyl thiophene
c. 2- chloro thiophene
d. 2-chloro, 5- methyl thiophene
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Ans. – a
173) Complete the reaction:
a. Cl2
b. SO3 + HCl
c. Cl2 + HCl
d. SO2Cl2
Ans. – d
174) What will be the product of the following reaction?
a. 2- iodo thiophene
b. 2,5 – di iodo thiophene
c. 2,3 – di iodo thiophene
d. Tetra iodo thiophene
Ans. – a
175) What will be the product of the following reaction?
a. 5 – bromo thiophene
b. 3- bromo thiophene
c. 2 – bromo thiophene
d. 2,5 – di bromo thiophene
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Ans. – c
176) Chlorination of thiophene by using Chlorine at 243K will form__________.
a. 2- chloro thiophene + 5- chloro thiophene
b. 2,5 – dichloro thiophene
c. 2- chloro thiophene + 2,5- dichloro thiophene
d. Tetra chloro thiophene
Ans. – c
177) Bromination of thiophene by using Bromine in benzene will produce________
a. 5 – bromo thiophene
b. 3- bromo thiophene
c. 2 – bromo thiophene
d. 2,5 – di bromo thiophene
Ans. – d
178) Identify the reaction:
a. Reimer Tiemann reaction
b. Canizzaro reaction
c. Vilsmeir – Hoack reaction
d. Benzoin condensation
Ans. – b
179) What would be the reducing agent for the following reduction of thiophene?
a. Na + ammonia
b. Hydrogen gas + Ni
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c. Pd + ammonia
d. Pd + Hydrogen gas
Ans. – a
180) Thiophene on catalytic reduction with large amount of palladium (Pd) gives_________.
a. 2 – thiolen
b. 3 – thiolen
c. n – Butane
d. Tetra hydro thiophene
Ans. – d
181) Thiophene is reduced with Raney nickel (Ni) which results in removal of sulphur to
form______.
a. 2 – thiolen
b. 3 – thiolen
c. n – Butane
d. Tetra hydro thiophene
Ans. – c
182) Which drug(s) contain thiophene ring in its(their) structure?
a. Cephalothin
b. Cefoxitin
c. Temocillin
d. All of the above
Ans. – d
183) Which drug(s) contain thiophene ring in its(their) structure?
a. Tinoridine
b. Tiaprofenic
c. Tenoxicam
d. All of the above
Ans. – d
184) Thiophene & its derivatives show following pharmacological activity.
a. Sedative
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b. Hypnotic
c. Anticonvulsant activity
d. All of the above
Ans. – d
185) Clotiazepam, CNS active agent, possess __________ heterocyclic ring.
a. Thiophene
b. Oxazole
c. Pyridine
d. Pyrrole
Ans. – a
186) Ticlopidine, anticoagulant activity, contain _________ heterocyclic compound.
a. Thiazole
b. Thiophene
c. Furan
d. Indole
Ans. – b
187) Which pharmacological effect is not produced by thiophene derivatives?
a. Anticoagulants
b. Diuretics
c. Coagulants
d. Anti asthmatics
Ans. – c
188) Thiophene probably undergoes to ___________ reaction.
a. Electrophilic substitution
b. Nucleophilic substitution
c. Electrophilic addition
d. Nucleophilic addition
Ans. – a
189) Furan probably undergoes to ___________ reaction.
a. Electrophilic substitution
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b. Nucleophilic substitution
c. Electrophilic addition
d. Nucleophilic addition
Ans. – a
190) Pyrrole probably undergoes to ___________ reaction.
a. Electrophilic substitution
b. Nucleophilic substitution
c. Electrophilic addition
d. Nucleophilic addition
Ans. – a