Electrophilic intramolecular cyclization of functional derivatives of unsaturated compounds: VI. Reaction of 2-(cyclohex-2-en-1-yl)acetanilides with arylsulfanyl chlorides. Structural and quantum chemical study of isomerization of 2-(2-arylsulfanyl-3-chlorocyclohexyl)acetanilides

2-(Cyclohex-2-en-1-yl)acetanilides react with arylsulfanyl chlorides in chloroform to give 2-(2-arylsulfanyl-3-chlorocyclohexyl)acetanilides which undergo isomerization into 2-chloro-3-arylsulfanylsubstituted derivatives in polar solvents. According to the results of quantum chemical calculations, the addition of arylsulfanyl chlorides to 2-(cyclohex-2-en-1-yl)acetanilides is characterized by negative Gibbs energy. Specific conformation of the isomerization products is stabilized by weak (non-covalent) interactions which make them more energetically favorable than the initial compounds. The reactions of 2-(cyclohex-2-en-1-yl)acetanilides with arylsulfanyl chlorides in nitromethane in the presence of lithium perchlorate lead to the formation of mixtures of the corresponding addition products and electrophilic intramolecular cyclization products, N-[7-(arylsulfanyl)octahydro-1-benzofuran-2-ylidene]anilinium perchlorates, which are converted into free bases by treatment with sodium ethoxide.