Cyclocondensation of dichloroethenes with alkanedichalcogenolates in the hydrazine hydrate – alkali system. The synthesis of dihydrodithiine and trihydrodichalcogenepines
摘要
Vinylidene chloride and 1,2-dichloroethene (a 1.3:1 mixture of Z- and E-isomers) reacted with 1,2-ethanedithiolate or 1,3-propane-dichalcogenolates (S, Se) under mild conditions to form cyclocondensation products. Alkanedichalcogenolates were generated from the corresponding oligomeric dichalcogenides by the action of a hydrazine hydrate – alkali reducing system and were used without isolation from the reaction mixture. 1,3-Propaneditellurolate did not form the corresponding heterocycle, regenerating poly(trimethylene ditelluride) during the reaction.