Identify the major product ( P ) in the following reaction:

Step-by-step solution

The given reactant is 4-methylcyclohex-2-en-1-one, which is an , -unsaturated ketone. The reagent ( CH ₃)₂ CuLi is a Gilman reagent (lithium dimethylcuprate). Gilman reagents are known to act as soft nucleophiles and preferentially undergo 1,4-conjugate addition to , -unsaturated carbonyl compounds, rather than 1,2-direct addition. In this reaction, the methyl carbanion ( CH ₃^- ) from the Gilman reagent attacks the -carbon (C3) of the , -unsaturated system. This breaks the carbon-carbon double bond and forms an en