Thiomaleic Anhydride: A Convenient Building Block for the Synthesis of α-Substituted γ- and δ-Lactones through Free-Radical Addition, Nucleophilic Ring Opening, and Subsequent Thiocarboxylate Manipulation
作者:David Crich、Md. Yeajur Rahaman
DOI:10.1021/jo901219k
日期:2009.9.4
carbonates and carbamates undergo clean free-radical addition to thiomaleic anhydride to give substituted thiosuccinic anhydrides in high yield on treatment with tris(trimethylsilyl)silane and a radical initiator. After removal of the tert-butyloxycarbonyl group, cyclization then affords lactones or lactams substituted in the α-position by a thiocarboxylic acid residue. This group is converted to amides through
在用三(三
甲基甲
硅烷基)
硅烷和自由基
引发剂处理后,
碘代烷基叔丁基
碳酸酯和
氨基甲酸酯与
硫代
马来酸酐发生干净的自由基加成,以高产率得到取代的
硫代
琥珀酸酐。除去叔丁
氧羰基后,环化得到在α-位被
硫代
羧酸残基取代的内
酯或内
酰胺。该基团通过与缺电子磺
酰胺反应转化为
酰胺,或通过衍生
硫酯与
苯硫酚、缺电子
烯丙基
苯基
硫醚或
苯基
硼酸反应转化为醛和/或
酮。