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.
7-
萘并[1,2-c][1,2]二
硫杂
环戊烯-3-
硫酮(7)、1-
萘并[2,1-c][1,2]二
硫杂
环戊烯-1-
硫酮(10)和3-
萘并[2,3-c][1,2]二
硫杂
环戊烯-3-
硫酮(16)与
环己烯和
2,3-二甲基-2-丁烯的光
化学反应可生成相应的
萘并
硫代醌亚甲基。其中7-
萘并
硫代醌亚甲基仅以单体形式存在,它是第一个可分离的邻位
硫代醌亚甲基;而16-
萘并
硫代醌亚甲基在固态下以[4+4]型二聚体形式存在,尽管其
化学行为表明在溶液中存在极少量的单体形式。关于10-
萘并
硫代醌亚甲基,单体和[4+2]型二聚体之间存在平衡。此外,还描述了这些
硫代醌亚甲基的一些环加成反应。