Sulfenyl chlorides, photolysis

The elimination of HC1 from the corresponding sulfenyl chlorides has been used in the synthesis of thioacetaldehyde182. The removal of HC1 was accomplished by photolysis of ethanesulfenyl chloride in an argon matrix at 12 K (equation 70). 

Thermolysis of the eight-membered heterocycle 248 (prepared from trisilylated benzamidine 205 and phenyl sulfenyl chloride, followed by S-oxidation) resulted in ring contraction and formation of the 1,2,4,6-thiatriazine 249 (Scheme 48). Photolysis (254nm) of 248 in toluene at 25 °C also afforded 249, but the thermolysis procedure was cleaner <2000IC1697>. 

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