Synthesis of the AE bicyclic of Daphniphyllum alkaloid yuzurine

A concise synthesis of the AE bicyclic system of Daphniphyllum alkaloid yuzurine is described. The synthetic sequence features a Dieckmann condensation to construct ring A, reduction of α, β-unsaturated double bond and propargylation of α-position of lactone to diastereoselectively generate relative stereocenter C-3, C-4 and C-5, and an acid-catalyzed cyclization to assemble ring E.