The title compounds were prepared by variations of a route in which the principal stages include conversion of N-substituted pyrrolidine-2-thiones 6 into vinylogous urethanes 10, which undergo subsequent cycloacylation. A related approach that uses a Robinson annulation was also partly successful.
通过改变路线的方法来制备标题化合物,其中主要阶段包括将N-取代的
吡咯烷-2-
硫酮6转化为
乙烯基的
氨基甲酸酯10,然后进行随后的环酰化。使用罗宾逊环法的相关方法也部分成功。