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.
S-酰基(芳酰)
硫水杨酸 2 与 N-
苯基(
三苯基膦烯基)乙
亚胺 3 进行逐步反应,生成酰基膦盐 5,随后在
硫酯羰基上经历分子内维蒂希环化,优良地生成 4H-1-
苯并噻吩并-4-
酮 7。