Stereoselective synthesis of the 6,7,6- and 6,7,7-ring systems of polycyclic ethers by 6-endo cyclization and ring expansion

Article abstract of DOI:10.1016/S0040-4020(97)00816-8

A new strategy for the stereoselective synthesis of the trans-fused seven-membered cyclic ethers corresponding to subunits of brevetoxin B and hemibrevetoxin B has been developed. The strategy involves alkylation of an oxiranyl anion and B-endo cyclization followed by one-carbon homologation of a tetrahydropyran to an oxepane using trimethylsilyldiazomethane.