Identify the starting compound A in the following reaction sequence:

Step-by-step solution

The reagent NaOI followed by H^+ performs the iodoform reaction, converting methyl ketones ( -COCH₃ ) into carboxylic acids ( -COOH ). Thus, compound A must contain a -COCH₃ group. Compound B is heated to yield 2-methylcyclohexanone. The loss of CO₂ upon heating indicates that B is a -keto acid, as they readily undergo decarboxylation. Working backwards from the product 2-methylcyclohexanone, the -COOH group in B must be located at the -carbon relative to the ketone. If the -COOH is at the C2 position, compound B i