Diaryl sulfoxidesbearing ortho-sulfur substituents react readily with Grignard reagents on the sulfur atom to produce the corresponding phenyl Grignard reagents bearing ortho-sulfur functional group. Furthermore, thianthrene monooxide was found to react with alkyl Grignard reagents affording o,o′-bis-Grignard reagent of diphenyl sulfide which was converted easily to Martin’s sulfurane.