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。