An efficient approach to the synthesis of 4H-1-benzothiopyran-4-ones via intramolecular Wittig reaction

P Kumar, AT Rao, B Pandey

Index: Kumar, Pradeep; Rao, Ashok T.; Pandey, Bipin Journal of the Chemical Society, Chemical Communications, 1992 , # 21 p. 1580 - 1581

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Citation Number: 2

Abstract

The reaction of S-acyl (aroyl) thiosalicylic acids 2 with N-phenyl ( triphenylphosphoranylidene) ethenimine 3 in stepwise fashion leads to the acylphosphoranes 5 which subsequently undergo intramolecular Wittig cyclization on the thiolester carbonyl to afford the 4H-1-benzothiopyran-4-ones 7 in excellent yields.