Abstract: The thermolysis of 2-chloro-3, 3-diethoxythietane 1, l-dioxide (24) at 230-250" affords a 95% yield of ethyl acetate, together with sulfur dioxide and ethyl chloride. Analogously, 2-chloro-3-thietanone 1, l-dioxide ethylene ketal (13b) gives rise to 2- chloroethyl acetate (86.5%) and sulfur dioxide. Two isomers of 2-chloro-3-thietanone 1, l- dioxide 1', 2'-propylene ketal (possibly 18 and 20) have also been prepared; both ...