Stereoselective Synthesis of <i>cis</i>-2,5-Disubstituted Tetrahydrofurans: An Approach to Pamamycins

A stereoselective synthesis of 2,5-cis-disubstituted tetrahydrofurans has been devised based on the epoxidation and rearrangement of products prepared from aldehydes with remote induction using allylstannanes and tin(IV) halides. This chemistry has been applied to synthesize the tetrahydrofuran containing fragments of (-)-nonactic acid and the pamamycins.