Identify the major product formed in the following reaction sequence.

Step-by-step solution

The given starting molecule contains both an ester group and an aldehyde group. In the first step, the reaction with ethylene glycol ( HO-(CH₂)₂-OH ) in the presence of an acid catalyst ( H^+ ) leads to the protection of the carbonyl group. Since aldehydes are more reactive towards nucleophilic addition than esters, the aldehyde group is selectively protected as a cyclic acetal. The intermediate formed is MeO-C(=O)-CH₂-CH(OCH₂CH₂O) . In the second step, this intermediate is treated with excess methylmagnesium bromi