The base-catalyzed reaction of diketosulfides (RCOCH2)2S (R=phenyl, p-tolyl) with biacetyl or benzil have provided high yields of 2,5-diacyltetrahydrothiophene-3,4-diol derivatives rather than the expected 2,5-diacylthiophenes. The diols have been transformed cleanly into the corresponding 2,5-diacylthiophenes by treatment with thionyl chloride-pyridine. In contrast, the reaction of the diketo sulfide (R=p-tolyl) with phenylglyoxal afforded a 2,5-diacylthiophene directly in good yield.
在碱催化下,二酮
硫化物 (RCOCH2)2S (R=phenyl, p-tolyl) 与
生物乙酰基或苯偶酰发生反应,产生了高产率的 2,5-二酰四氢
噻吩-3,4-二醇衍
生物,而不是预期的 2,5-二酰
噻吩。通过亚
硫酰氯-
吡啶处理,这些二元醇被干净利落地转化为相应的
2,5-二乙酰基噻吩。相反,二酮
硫醚(R=p-
甲苯基)与苯基
乙二醛反应后,可直接生成
2,5-二乙酰基噻吩,收率很高。