Identify the major product of the following reaction:

Step-by-step solution

The given reactant is a 2,3-epoxy alcohol derivative, specifically attached to a 1,3-dioxolane ring. The side chain is -CH(O)CH-CH₂OH . When a 2,3-epoxy alcohol is treated with a nucleophile (such as PhS^- from PhSNa ) in an aqueous or protic medium, it typically undergoes a Payne rearrangement. The base or the nucleophile facilitates the reversible intramolecular migration of the epoxide from the internal position to the terminal position: R-CH(O)CH-CH₂OH R-CH(OH)-CH(O)CH₂ Although the equilibrium generally favors