Abstract
Photochemical thiylation of 2'-vinyl-2H-benzothiazine-2-spirocyclopropan-3(4H)-ones (1) to form allyl sulfides (3) was examined. Although the reactions proceeded with complete regioselectivity because of the high stabilizing ability of the capto-dative substituents, geometrical selectivity of the olefinic moiety was dependent on the substituents on the cyclopropane ring. The conformation of 1 probably plays an important role in the addition step of the thiyl radical to the double bond.
