Various approaches to the syntheses of 5-substituted-3-carbomethoxy-2,5-dihydrothiophenes and their product sulfolenes, required as synthetic precursors for tangutorine, are described. An efficient route to 3,5-disubstituted-4,5-dihydrothiophenes and hence 3,5-disubstituted-2-sulfolenes by radical chemistry is also described.
描述了合成作为桔梗碱的合成前体所需的5-取代的-3-羰基甲氧基-
2,5-二氢噻吩及其产物亚砜的各种方法。还描述了通过自由基
化学反应制备3,5-二取代的4,5-二氢
噻吩并因此得到3,5-二取代的-2-亚砜基的有效途径。