Question

t-butyl $-C=CH-\underset{O}{\underset{||}{C}}-OH$ can't give decarboxylation while normally $\alpha -\beta$ unsaturated acid give this reaction because:

• A. t-butyl gp, has large size and does not let the $COOH$ group to leave.
• B. t-butyl gp. can't extract $H$ from $COOH$
• C. t-butyl gp. destabilise carbanion formed
• D. t-buty gp, does not allow this composition to convert to $\beta -\gamma$ unsaturated acid

Answer 1

Answer: (C)

t-butyl gp. destabilise carbanion formed

The reason is because of $+I$ effect, t-butyl group destabilises the carbanion. Therefore t-butyl group can't give decarboxylation.