Studies on the regio- and stereoselectivity of halohydroxylation of 1,2-allenyl sulfides or selenides

The halohydroxylation of 1,2-allenyl sulfides or selenides with Br(sub 2) (CuBr(sub 2) or NBS) or I(sub 2) and water demonstrate a fair good regioselectivity leading to the synthesis of synthetically important 3-organosulfur or seleno-2-haloallylic alcohols. The conclusion states that the stereoselectivity depends on the nature of X(super +) and S or Se, showing a Z-selectivity with the matched Lewis acid-base pair.