Active methylene compounds

Preparation,Synthetic applications

1. Active Methylene Compounds
DrBincyJoseph
ASSISTANTPROFESSOR
DEPARTMENT OFCHEMISTRY
ST.MARY’SCOLLEGE,THRISSUR
ACTIVE METHYLENE COMPOUNDS,DR.BINCYJOSEPH,ST.MARY'SCOLLEGE,THRISSUR.

2. Reactive Methylene group
A methylene group (-CH
2-) present between two electron
withdrawing groups like -C=0 or –CN.
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

3. Reactive Methylene compounds
Diethyl malonateor malonicester
Ethyl acetoacetate or acetoacetic ester
ethyl cyanoaceteteor cyanoaceticester
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

4. Keto-enol tautomerism in active methylene
compounds
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

5. Keto-enol tautomerism
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

6. Keto-enol tautomerism
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

7. Ethyl acetoacetate or acetoacetic ester
Ethyl ester of acetoacetic acid, a β-ketoacid.
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

8. Preparation-Claisen condensation
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

9. Mechanism
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

10. Mechanism…..
Step 3 : Collapse of the tetrahedral carbonyl addition intermediate by elimination of
the alkoxideleaving group to give the β-ketoester.
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

11. Mechanism…
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

12. Mechanism…..
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

13. Synthetic uses
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

14. a. Acidity of –CH
2-group: salt formation
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

15. b.Alkylationof acetoacetic ester anion
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

16. Formation of Alkyl acetoacetic esters
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

17. Synthetic applications of acetoacetic ester
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

18. 1.Synthesis of monocarboxylic acids
a.Conversion to acetic acid
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

19. b.Synthesis of alkylacetic acids
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

20. Synthesis of butanoic acids
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

21. synthesis of dialkylaceticacids
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

22. Synthesis of 2-methylpropanoic acid
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

23. a.Synthesis of succinic acid
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

24. b.Synthesis of glutaric acid
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

25. c. Synthesis ofadipicacid
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

26. 3.Synthesis of α,β-unsaturated acids
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

27. 4.Synthesis of β-ketonicacids
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

28. 5.Synthesis of Ketones
a.Synthesis of Acetone
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

29. b. Synthesis of Butanone
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

30. c. Synthesis of 3-methylpentan-2-one
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

31. 6.Synthesis of 1,3-diketones
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

32. 7.Synthesis of 1,4-diketones
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

33. 8. Synthesis of Hydrocarbons
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

34. 9. Synthesis of Heterocyclic compounds
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.

35. Thank You
ACTIVE METHYLENE COMPOUNDS,DR.BINCY JOSEPH,ST.MARY'S COLLEGE,THRISSUR.