A short and efficient synthesis of (+)-totarol

A concise route to multigram quantities of the antibacterial diterpene (+)-totarol (1) is reported.(-)-Sclareol (2) was converted to the target compound 1 using either a six-or a seven-step sequence, while only three steps were required to access (+)-totarol (1) starting from (+)-manool (9) or (+)-13-epi-manool (10), respectively.A novel one-pot intramolecular aldol condensation/ -alkylation protocol served as the key operation for streamlining the syntheses of 1.