Several monomethylsubstituted 3-aminotetrahydrothiophene-3-carboxylic acids have been synthesized from the corresponding 3-ketotetrahydrothiophenes by the Strecker and the Bucherer-Bergs syntheses. In each case, the former synthesis leads to one stereoisomer, and the latter, to the opposite stereoisomer. The configurations of 3-amino-2-methyltetrahydrothiophene-3-carboxylic acids have been determined by a study of the NMR spectra; the others have been estimated on the basis of these results. The configurations do not contradict those first assigned to the alkyl substituted 1-amino-1-cyclohexanecarboxylic acids.
几种单甲基取代的 3-aminotetrahydrothiophene-3-carboxylic acids 是通过 Strecker 和 Bucherer-Bergs 合成法从相应的 3-ketotetrahydrothiophenes 合成的。在每种情况下,前一种合成方法会产生一种立体异构体,而后一种合成方法则会产生相反的立体异构体。3-amino-2-methyltetrahydrothiophene-3-carboxylic acids(3-
氨基-
2-甲基四氢噻吩-3-
羧酸)的构型是通过核磁共振光谱研究确定的;其他构型则是根据这些结果估计的。这些构型与最初分配给烷基取代的 1-
氨基-1-
环己烷羧酸的构型并不矛盾。