Halohydroxylation of 1-cyclopropylallenes: An efficient and stereoselective method for the preparation of multisubstituted olefins

The halohydroxylation of 1-cyclopropylallenes would generate two multisubstituted C=C double bonds and at the same time stereoselectively gives 5-halohexa-3,5-dien-1-ols in moderate to good yields. The latter could be transformed into the corresponding alkynyl-substituted conjugated dienes through the further Sonogashira coupling.