Scheme IV selenide 9 by treatment with NCS in 81% yield (eq 2). In contrast, y-hydroxy selenide 10 (a mixture of threo and erythro, 1: 2) was exclusively deselenized to give allylic alcohol 11 (cis/trans, 3: 7) and diphenyl diselenide in 97% and 40% yields, respectively, under similar conditions. When this reaction was carried out for a longer time, the yield of 11 was gradually decreased (-75%), and formation of enone 12 (-15%) and diene 13 (-5%) ...
