Synthesis and Reactions of o-Naphthothioquinone Methides

Article abstract of DOI:10.1246/bcsj.55.243

Photochemical reactions of naphtho<1,2-c><1,2>dithiole-3-thione (7), naphtho<2,1-c><1,2>dithiole-1-thione (10), and naphtho<2,3-c><1,2>dithiole-3-thione (16) with cyclohexene and 2,3-dimethyl-2-butene afford the corresponding naphthothioquinone methides.The thioquinone methide from 7 exists only as a monomeric form and is the first isolable o-thioquinone methide, while that from 16 exists as a dimer of <4+4> type in the solid state although the chemical behavior suggests the presence of a monomeric form in solution to a very minor extent.In the case of the thioquinone methide from 10, there exists an equilibrium between a monomer and a dimer of <4+2> type.Some cycloadditions of these thioquinone methides are also described.