Question

The correct statement regarding a carbonyl compound with a hydrogen atom on its alpha carbon, is :

• A. a carbonyl compound with a hydrogen atom on its alpha-carbon never equilibrates with its corresponding enol
• B. a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as aldehyde-ketone equilibration
• C. a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as carbonylation
• D. a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as keto-enol tautomerism

Answer 1

Answer: (D)

a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as keto-enol tautomerism

The correct statement regarding a carbonyl compound with a hydrogen atom on its alpha carbon, is given by the option D.
"A carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as keto-enol tautomerism."
For example, the keto enol tautomerism for acetaldehyde is as shown.
$C{H}_{3}CHO\rightleftharpoons C{H}_2=CHOH$
The inter conversion of the two forms (keto and enol) involves the movement of an alpha hydrogen and the shifting of bonding electrons.