Question

How do you explain keto-enol tautomerism?

Answer 1

This is a bond-forming reaction that occurs extensively in 1,3-dicarbonyl species.......

Explanation:

`RC(=O)CH_2(O=C)R rightleftharpoonsRC(=O)CH=(COH)R`

The resultant enol gives an (energetically stable) 6-membered ring that is stabilized by hydrogen bonding. This delocalization of electrons allows removal of the proton by a strong base to give the enolate, whose alternative carbanion structure facilitates one of the few `C-C` bond formation reactions.

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