TMSI-Promoted Vinylogous Michael Addition of Siloxyfuran to 2-Substituted Chromones: A General Approach for the Total Synthesis of Chromanone Lactone Natural Products

A concise and facile synthetic protocol for the construction of the 2-γ-lactone chromanone skeleton has been achieved through a TMSI-promoted diastereoselective vinylogous Michael addition of siloxyfuran to 2-substituted chromones. The applicability of this method is demonstrated through the rapid access to the total syntheses of (±)-microdiplodiasone, (±)-lachnone C, and (±)-gonytolides C and G.