Highly efficient chemical kinetic resolution of bishomoallylic alcohols: synthesis of (R)-sulcatol.

A highly efficient chemical kinetic resolution of bishomoallylic alcohols was developed when the alcohols underwent In(OTf)3-catalyzed 3,5-oxonium-ene-type cyclization with steroidal aldehyde 2. Consistently high enantiomeric excess (up to >99%) was obtained.