Synthetic Studies of Isoschizogamine: Alternative Preparation of the Key Intermediate

An alternative synthetic route toward a key intermediate in the total synthesis of isoschizogamine is described. The Claisen-Johnson rearrangement stereoselectively constructed a quaternary carbon. Trifluo-roperacetic acid mediated the Baeyer-Villiger oxidation to form a bicyclic lactone. The Mukaiyama-Matsuo protocol converted the lactone into an alpha,beta-unsaturated lactone, that was used as the substrate for the rhodium-mediated 1,4-addition of an arylboronic acid.