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.

中文翻译：

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（三甲基甲硅烷基）亚甲基三苯基磷烷新合成4 H -1-苯并噻喃-4-酮

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。