Identify the major product formed in the following reaction sequence.

Step-by-step solution

The given reactant is a bicyclic compound, specifically a fused system of two 5-membered rings: a tetrahydrofuran ring and a -lactone ring. Its structure is hexahydrofuro[2,3-b]furan-2-one. Reaction with aqueous NaOH Aqueous NaOH hydrolyzes the lactone ring. The hydroxide ion attacks the carbonyl carbon, breaking the acyl-oxygen bond. This opens the -lactone ring, forming the sodium salt of a carboxylic acid and leaving a hydroxyl group at the bridgehead carbon (which is an acetal carbon). The intermediate formed a