Predict the major product of the following reaction sequence: (i) Excess LiAlH ₄ , then H ₃ O ⁺ (ii) Ethanal, catalytic H ⁺ , heat

Step-by-step solution

The given starting material is methyl 3-oxopropanoate. Excess LiAlH ₄ is a strong reducing agent that reduces both the ester and aldehyde groups to primary alcohols. MeOOC - CH ₂- CHO LiAlH ₄ HO - CH ₂- CH ₂- CH ₂- OH The resulting product is propane-1,3-diol. Propane-1,3-diol then reacts with ethanal ( CH ₃ CHO ) in the presence of an acid catalyst to form a cyclic acetal. The two - OH groups condense with the carbonyl carbon of ethanal, eliminating water to form a six-membered 1,3-dioxane ring with a methyl group