Sulfoxide-controlled SN2′ displacements between cuprates and vinyl and alkynyl epoxy sulfoxides

The SN2′ displacement of readily available vinyl epoxy sulfoxides with organocopper reagents takes place in good yields with high anti selectivity and a good degree of E/Z stereocontrol to produce enantiopure α-hydroxy vinyl sulfoxides. A second allylic displacement on the related mesyloxy vinyl sulfoxides allows for the asymmetric construction of two adjacent chiral centers. In addition, cuprate mediated SN2′ addition to alkynyl epoxy sulfoxides affords α-hydroxy allenyl sulfoxides in good yields.