reactions. In contrast to numerous literature reports, all but one of the 16 reactions studied were found to give nearly the same amount of both possible A-homo products. (The single exception was the only reaction in which the A-homo product reacts markedly faster than the starting material.) This simple, consistent ∼1:1 pattern is that expected if migration is governed mainly by ...
已经重新检查了 3-
酮类固醇的几种扩环反应(
重氮甲烷、
重氮乙酸酯、Tiffeneau-Demjanov、Baeyer-Villiger 和 Schmidt),以确定这些不对称
环己酮中 C-2 和 C-4 的真实迁移率。通过在总反应产物的质子去耦 13Cmr 光谱中积分基线分离信号,测量迁移率达到 ±3% 的准确度。这种未充分利用的方法首次提供了一种在分离过程中不损失组分且不受过量起始材料干扰的方法,可以在最大限度地减少副反应的条件下获得准确的迁移率。与大量文献报道相反,发现所研究的 16 个反应中除了一个反应外,所有可能的 A-均产物的量几乎相同。