中文摘要：

通过1HNMR，NOE和x—ray等方法，确定了S-（2-乙酰苯基）二甲基硫代氨基甲酸酯在NaH／DMF条件下的环合产物为苯并-2H-噻喃-2-酮，而非文献报道的苯并-4H-噻喃-4-酮．探讨了苯并-2H-噻喃-2-酮和苯并-4H噻喃-4-酮结构在氢谱上的规律性差异．

英文摘要：

The structure of cyclization product from the reaction of S-2-acetylphenyl dimethylthiocarbamate with Nail in DMF was clarified by 1H NMR, NOE and X-ray. It proved to be a benzo-2H-thiopyran-2-one instead of a benzo-4H- thiopyran-4-one reported in literature. The 1H MNR chemical shift data of seven benzo-2H-thiopyran-2-ones and benzo-4H- thiopyran-4-ones were discussed, which might be useful for distinguishing benzo-2H-thiopyran-2-ones from benzo-4H- thiopyran-4-ones.