Solutions to Problems Alcohols, Building Bridges to Knowledge

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SolutionstoProblemsAlcohols

BuildingBridgestoKnowledge

Photo of a stream in near Salt Lake City, Utah. Michaelle Cadet

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1. Arrange the following compounds in order of increasing boiling points.

(a) n-pentanol (b) 2-methyl-2-butanol

(c) 3-methyl-2-butanol (d) 2,2-dimethylpropanol

The molecule that has the most spherical structure would have the lowest boiling point, and the molecule with the most linear structure would have the highest boiling point; therefore, the boiling points would be:

(a) > (c) > (b) > (d) 2. Predict the products expected when 2-methyl-1-butanol reacts

with:

(a) Phosphorous and iodine

(b) Ethyl magnesium bromide

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(c) tosyl chloride in HCl

(d) chromic acid

(e) sulfuric acid/heat

3. Suggest syntheses for the following from 1-butanol and any

other necessary inorganic or organic materials.

(a) n-octane

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(b) trans-3-octene

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(c) cis-3-octene

Use the same sequence of reactions in (b) to prepare 3-octyne, than treat 3-octyne with the Lindlar catalyst.

(d) 1,2-butanol

(e) ethylcyclopropane

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(f) butanoic acid

(g) 1-butyne

1-butyne has been synthesized from 1-butanol in “(b).”

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(h) butanal

(l) 1-iodobutane

4. Suggest a synthesis for the following from the indicated starting

material and any other necessary inorganic reagent.

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5. Suggest a synthesis for the following from the indicated starting

material and any necessary inorganic material.

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6. Give a rationale for the following reaction.

The tosyl group is a facile leaving group, and elimination occurs in a trans configuration. The tosyl group and H2 are in the cis configuration; therefore, H2 will not be removed during the elimination process. On the other hand, H1 is trans to the tosyl group; therefore, H1 is the preferred hydrogen atom that will be removed during the elimination process.

or

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7. A monoterpenoid found in some essential oils (e.g., rose oil) follows the isoprene rule and exhibits the following 13C NMR spectrum. The infrared spectrum of the monoterpenoid exhibits a strong transmittance band at 3333 cm-1 .

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Ozonolysis of the monoterpenoid produces the following three compounds.

Suggest a structure for this monoterpenoid that is consistent with the observed data.

6. An important biological material with the molecular formula C21H40O can be synthesized by treating 1-hexyne with sodium amide, followed by treating the resulting product with 1-chloro-3-iodopropane, followed by treating the resulting product with magnesium in dry ether, followed by treating the resulting product with n-undecanal, followed by acid hydrolysis. The product of this final reaction is reacted with hydrogen/Pd/ PbO/CaCO3. The resulting product is oxidized to C21H40O. Suggest a structure for C21H40O.

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(1)

(2)

(3)

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(4)

(5)

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(6)

8. Suggest products for the following reactions.

(a)

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(b)

(c)

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(d)

9. Suggest a synthesis for the following compound from the indicated starting materials and any other necessary organic and inorganic materials.

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11. Suggest a structure for

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12. Suggest a synthesis for the following molecule from the given

starting material and any other necessary organic or inorganic materials.

13. Suggest syntheses for the following molecules from 1-butanol

as the only source of organic compound and any necessary inorganic materials.

(a) n-butyl mercaptan

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(b) 4-octanol

Prepare the appropriate alkyl halide from 1-butanol.

Prepare the appropriate Grignard reagent from the alkyl halide.

Prepare butanal from 1-butanol.

React the Grignard reagent with butanal.

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(c)

4-Octanone, (c), can be prepared by the oxidation of the product of (b), 4-octanol.

(d)

Prepare 2-butanone from 1-butanol using the following sequence of reactions:

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React the Grignard reagent with 2-butanone

14. Suggest a synthesis for the following molecule from the

indicated starting material and any other necessary inorganic material.

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15. Suggest a mechanism for the following conversion.

(1)

(2)

(3)

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(4)

(5)