Identify the major product of the following reaction:

Step-by-step solution

The given reactant is 2-furylglyoxal, an -ketoaldehyde. Treatment with concentrated base followed by acidic workup results in an intramolecular Cannizzaro reaction. The hydroxide ion ( OH⁻ ) attacks the more electrophilic aldehyde carbonyl carbon to form a tetrahedral intermediate. A 1,2-hydride shift occurs from the aldehyde carbon to the adjacent ketone carbonyl carbon. Rapid intramolecular proton transfer then forms a stable carboxylate ion. R-CO-CHO + OH⁻ R-CO-CH(OH)-O⁻ R-CO-CH(OH)-O⁻ R-C(O⁻)(H)-COOH R-C(O⁻)(H)