Abstract A concise and step-economical total synthesis of biologically active frutinones has been achieved. Tributylphosphine (PBu 3) efficiently induced the tandem acyl transfer- cyclization of carbonates 5 to afford 3-methoxycarbonylflavone derivatives 4 in excellent yields. Finally, concomitant deprotection and lactonization under acidic conditions furnished the desired frutinones A (1a), B (1b), and the proposed structure of frutinone C (1c).
