“…It was an efficient method for the preparation of 3-substituted thietanes 400 from (1-haloalkyl)thiiranes 398 through an intramolecular nucleophilic substitution followed by an intermolecu-lar nucleophilic displacement with the in-situ generated 1-thiabicyclo[1.1.0]butan-1-iums 399 as key intermediates. Following this route, 3-substituted thietanes 400 were prepared from reactions of 2-(1-chloroalkyl)thiiranes 398, especially chloromethylthiirane (epithiochlorohydrin, 398a), with hard and weak nucleophiles [105][106][107][108][109], including phenoxides [105], carboxylates and dicarboxylates [106,107], potassium cyanide, sodium azide, hydroxylamine, trifluoromethanesulfonamide, and pyridine [108]. However, the method could only applied to the synthesis of 3-substituted thietanes 400 from (1-chloroalkyl)thiiranes 398 (Scheme 84).…”