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甾体全合成的研究虽已有四十多年历史,但迄今只有消旋的甾体化合物可用全合成方法进行工业规模的生产。光学活性的甾体化合物可用半合成的方法如从薯蓣皂素或胆固醇得到;而用全合成的方法则需用化学或微生物方法拆分才能得到所需要的对映异构体。比较有效的方法是在合成早期拆分较简单的中间体。一般拆分的操作是冗长与繁锁的,理论收率仅为50％,实际上还要低得多。 不对称合成,可以不经拆分就得到所需的对映异构体,光学纯度甚至可达100％。这个方法现已在天然产物全合成领域中被广泛地研究和应用,并在甾体全合成中获得较大的成功,特别是为制备某些不能
Although the study of steroidogenesis has been more than 40 years old, only racemic steroid compounds have so far been produced on an industrial scale by total synthesis. Optically active steroids can be obtained by semisynthetic methods such as diosgenin or cholesterol; whereas fully synthetic methods require resolution by chemical or microbial means to obtain the desired enantiomer. A more effective method is to split simpler intermediates early in the synthesis. General split operation is lengthy and cumbersome, the theoretical yield was only 50%, in fact much lower. Asymmetric synthesis, you can get the desired enantiomers without resolution, the optical purity even up to 100%. This method has been extensively studied and applied in the field of total synthesis of natural products and has been greatly successful in the synthesis of steroids. In particular,