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