Mechanism & reaction

Presented By

Mr. Kiran R. Dhangar

( M. Pharm ) IST SEM

Dept. of Pharmaceutical Chemistry

RCPIPER, Shirpur 425405

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1.Introduction

2.Definition

3.General Reaction

4.Reaction Mechanism

5.Stereochemistry

6.Applications

7.References2

The Beckmann rearrangement, named after the German

chemist Ernst Otto Beckmann (1853–1923).

The acid catalyzed rearrangement involving the conversion

of ketoximes into amide is known as the Beckmann

rearrangement.

A variety of acidic reagents such as H3PO2, H2SO4, P2O5,

SOCl2 and PCl5 have been found to catalyze this

rearrangement.3

If oxime is not derived from a ketone but an aldehyde then a nitrile is formed.

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The Beckmann rearrangement is an acid catalyzed

transformation of a ketoxime, the oxime of a ketone to an amide,

Acid converts the oxime hydroxy to a good leaving group and

promotes arrangement of an adjacent aryl or alkyl group.

Retention of configuration.

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Determination of configuration of ketoxime:

Hydrolysis

Synthesis of Isoquinoline:

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Synthesis of ∑-caprolactum:

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Victor Grignard

Grignard Reagents

• Discovered by Victor Grignard in 1900

– Key factors are etheral solvent and water-free conditions

• Awarded Nobel Prize in 1912

Grignard, Victor , 1871–1935, French chemist. He shared the 1912 Nobel Prize in Chemistry for his work in organic synthesis based on his discovery (1900) of the Grignard Reagent. He taught at the Univ. of Nancy (1909–19) and at the Univ. of Lyons (from 1919 until the end of his career).

The First Organometallic Reagents…

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Organometallic compound:A compound that contains a carbon-metal

bond.

Organometallic Reagents

The Key Concepts:

Make a carbon negatively charged/polarized so it

is nucleophilic.

Reaction with electrophilic carbons can make

carbon-carbon bonds.

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Grignard Reaction:

The addition of Grignard reagent to aldehydes

and ketones is known as the Grignard reaction.

RX Mg RMgX

A Grignard Reagent

+Anhydrous

ether

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RMgX

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Synthesis of alcohol

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Synthesis of Triphenylmethanol

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Grignard reaction is a key step in the industrial

production of Tamoxifen:

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1. Jerry March, Advanced Organic Chemistry, Reaction, Mechanism andstructure, fourth edition, Wiley publishing house, page no.1095-1096

2. Stanley H. Pine, Organic Chemistry , fifth edition, page no.987

3. G.R. Chatwal, Reaction Mechanism and reagents in Organic Chemistry,fifth edition 2012, Himalaya Publishing house, page no.16.28-16.32

4. O. P. Agarawal, Organic Chemistry Reaction and Reagents, 48th Edition,GOEL publishing house 2012, page no.539-540

5. Solomon And Fryhle , Organic Chemistry, 18th edition, Wiley publishinghouse,2004, page no.552-562

6. Joshua Howrth , Core Organic Chemistry, first edition , Wiley publication,Singapore 1998, page no. 149

Beckmann rearrangement

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7. Ernest L. Eliel, Stereochemistry of Carbon Compounds,first edition, Tata

McGraw Hill Edition,2010, page no.120,323-324.

8. Chandrasekhar, S.; Gopalaiah, K. Beckmann reaction of oximes catalyzed by

chloral: Mild and neutral procedures. Tetrahedron Lett. 2003, 44, 755–756.

9. Douglass F. Taber , Patrick J. Straney, The Synthesis of Laurolactam from

Cyclododecanone via a Beckmann Rearrangement, Journal of Chemical

Education 2006, 2-13.

Grignard Rearrangement

1. Jerry March, Advanced Organic Chemistry, Reaction, Mechanism andstructure, Wiley publishing house, fourth edition, page no.920-929

2. Robert Thornton Morrison, Robert Neilson Boyd and Saibal kantiBhattacharyajee, Organic Chemistry, Pearson publication, Seventh edition,page no.143-145.

3. G.R. Chatwal, Reaction Mechanism and reagents in Organic Chemistry,Himalaya Publishing house, fifth edition 2012 , page no.9.9-9.11

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4. O. P. Agarawal, Organic Chemistry Reaction and Reagents, 48th Edition, GOELpublishing house 2012, page no.953-954

5. Joshua Howrth , Core Organic Chemistry, first edition , Wiley publication,Singapore 1998, page no. 13, 92, 95, 105, 111, 138, 153, 514.

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End of Lecture. Any Questions?

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