Synthesis of γ-Quaternary Acylcyclopentenes via a Ring-Contraction Strategy

Significance

The authors describe a catalytic enantioselective allylation-ring-contraction sequence for the synthesis of densely functionalized chiral acylcyclopentenes. The palladium-catalyzed asymmetric alkylation affords precursors in excellent yields and high enantioselectivities. The subsequent mild ring contraction via a retro aldol-­aldol sequence affords important chiral building blocks.