Steroids and their des-A- and des-AB-derivs. of partial formula (I): (where R1 is Me or Et; R2 is H or lower acyl, and R3 stands for the opt. substd. rings ABC, BC or C of a steroid molecule), which are useful as inters. for pharmaceuticals, are prepd. by subjecting a corresp. cpd. of partial formula (II): (where R4 is lower acyl and X is Cl, Br or I) to partial dehalogenation with a reducing agent (pref. CrCl2 or trialkyl phosphite) to give the corresp. 17alpha-monohaloacetyl cpd., and subjecting this to heat treatment in a polar aprotic solvent in the presence of an alkali(ne earth) metal salt of a lower carboxylic acid to give (I; R2 = lower acyl) which may be saponified to give (I; R2 = H).
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机译：类固醇及其des-A和des-AB衍生物。部分式（I）的通式：（其中R 1是Me或Et; R 2是H或低级酰基，R 3代表类固醇分子的优选取代的环ABC，BC或C），它们可用作中间体。用于药品，需要准备。通过接受相应的修正。 cpd。部分式（II）的通式（其中R 4为低级酰基，X为Cl，Br或I）通过还原剂（优选为CrCl 2或亚磷酸三烷基酯）进行部分脱卤而得到相应的产物。 17α-单卤代乙酰基cpd。，并在极性非质子传递溶剂中，在低级羧酸的碱金属金属盐的存在下进行热处理，得到（I; R2 =低级酰基），可以将其皂化得到（I; R 2 = H）。
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