A new synthesis of 4H-1-benzothiopyran-4-ones using (trimethylsilyl)methylenetriphenylphosphorane
作者:Pradeep Kumar、Mandar S Bodas
DOI:10.1016/s0040-4020(01)00977-2
日期:2001.11
The reaction of silyl ester of S-acyl(aroyl) thiosalicylic acids 3 with (trimethylsilyl)methylenetriphenylphosphorane 4 in step wise fashion leads to the acylphosphoranes 7, which subsequently undergo intramolecular Wittig cyclization on the thiolester carbonyl to afford the 4H-1-benzothiopyran-4-ones 8 in good to excellent yields.
S-酰基(芳酰基)硫代水杨酸3的甲硅烷基酯与(三甲基甲硅烷基)亚甲基三苯基膦烷4的逐步反应导致酰基膦酸酯7,其随后在硫酯羰基上进行分子内Wittig环化,得到4 H -1-苯并噻喃-4-ones 8的产量好至极好。