Cyclization reactions of various thionoestera and thioamides involving the addition of tri-n- butylstannyl radical to a thiocarbonyl group and intramolecular addition of the resulting radical to a carbon-carbon multiple bond was studied. Dithiocarbonate and (imidazoly1) thiocarbonyl derivatives of homoallylic alcohols gave a-substituted ythionobutyrolactones. The reaction is highly dependent on the substitution pattern on the double bond, a high ...
