An efficient synthetic procedure for substituted 2,3,6,7-tetrahydrothiopyrano[2,3-b]thiopyran-4,5-diones by a double annulation strategy is described. The ring systems are made in good yields from readily available dialkenoylketene dithioacetals in the presence of either sodium sulfide nonahydrate/N,N-dimethylformamide (DMF) or a sodium hydride/DMF/amine system.
本文描述了一种通过双环化策略合成取代的2,3,6,7-
四氢噻喃并[2,3-b]
噻喃-4,5-二酮的高效合成方法。在九
水硫化
钠/
N,N-二甲基甲酰胺(
DMF)或氢化
钠/
DMF/胺体系存在下,可用易得的二烯酰基
烯酮二硫代缩醛制备环系统,且收率较高。