organic reaction

M.pharm 1 st year NIKET BAJARE pharmaceutical chemistry

1. ADVANCED ORGANIC CHEMISTRY Presented by : Niket D.Bajare [M.pharm First year] Guided by :Dr S. Pekamwar School of Pharmcy ,Nanded.

2. Mechanism and Synthetic Application of Naming reaction DIECKMANN REACTION OZONOLYSIS REACTION

3. DIECKMANN REACTION -It is named after the german chemist Walter Dieckmann (1869-1925) -certain diesters undergoes intramolecular condensation in the presence of strong base to produce B-keto esters this called as “Dieckmann condensation reaction”. -its ring forming reaction.

4. General Reaction :-

5. Mechanism....... -Deprotonation of an ester at the alpha-position generates an enolate ion which then undergoes a 5-exo-trig nucleophilic attack to give a cyclic enol. -protonation with a Bronsted-Lowry acid reforms the Beta-keto ester.

6. Mechanism.........

7. synthetic application.......... It is used in the synthesis of various cyclopentane &cyclohexane derivative. it is used in preparation of cyclic indole.(active against cancer)

8. OZONOLYSIS

9. what is ozonolysis ? OZONOLYSIS is an organic reaction where the unsaturated bonds of alkenes,alkynes or azo compound are cleaved with ozone . alkenes and alkynes form organic compound in which the multiple carbon-carbon bond has been replaced by a carbonyl group.while azo compound form nitrosamines. the out come of reaction depends on the type of multiple bond being oxidised and work up condition .

10. ozonolysis of alkenes............. alkenes can oxidised with ozone to form alcohol,aldehyde,or ketone or carboxylic acid. e.g- tetramethyl alkene which is undergoes ozonolysis in methanol at -78dc. to form the prop-2-one and small amount of acids.

11. reaction

12. Mechanism .... The alkene and ozone form an intermediate molozonide in a 1,3-dipolar cycloaddition. the molozonide reverts to its corresponding carbonyl oxide and aldehyde or ketone in a retro-1,3-dipolar cycloaddition. the oxide and aldehyde or ketone react again in a 1,3-dipolar cycloaddition or produce a relatively stable ozonide intermediate (a trioxolane )

13. Synthetic application.... It is used for structure elucidation of unknown organic compound containing carbon carbon double bond(c=c).

14. References :- Organic chemistry Clayden, Greeves,Warren & Woihers ., Oxford University. Wikipedia