Synthesis of 4-Aryl-2-sulfenyl-2 H -1-benzothiopyran Derivatives by Cyclization of [2-(1-Aryl-2-methoxyvinyl)phenylthio][methyl(or phenyl)thio]methyllithiums

4-Aryl-2-methyl(or phenyl)thio-2H-1-benzothiopyrans have been prepared in satisfactory yields from the corresponding 1-(1-aryl-2-methoxyethenyl)-2-{[methyl(or phenyl)thiomethyl]thio}benzenes via lithiation of the carbon atom between the two sulfur atoms, followed by intramolecular cyclization with loss of lithium methoxide.