Synthesis of (+)-Disparlure via Enantioselective Iodolactonization.

The BINOL-amidine organic catalyst 1 was previously shown to promote highly efficient enantioselective halolactonization reactions of olefinic acids. As part of these studies, it was discovered that the enantioenriched iodolactones could be easily converted into enantioenriched cis-1,2-disubstituted epoxides. This halolactonization-epoxidation sequence was applied to the synthesis of (+)-disparlure, which resulted in the shortest catalytic enantioselective synthesis to date, requiring only five steps and proceeding in 33% yield.