The intermediates and processes of this invention provide a new synthetic route for the preparation of pharmaceutically valuable 19-norsteroids. Further, the intermediates and processes of the invention provide a route for the preparation of pharmaceutically valuable estrones. The present invention provides a facile total synthesis of 19.beta.-alkyl-C/D-trans-steroidal materials. This desirable result is obtained via a unique asymmetric induction followed by subsequent stereo-specific reaction steps. As a precursor to the steroidal Ring A, a 3,5-disubstituted-4-isoxazolylmethylene group is employed in this synthesis.
本发明的中间体和过程为制备具有药用价值的19-去甲基类
固醇提供了一种新的合成途径。此外,本发明的中间体和过程为制备具有药用价值的
雌酮提供了一种途径。本发明提供了一种容易的19-β-烷基-C / D-顺式类
固醇材料的全合成。通过独特的不对称诱导后跟随的立体特异性反应步骤,获得了这种理想的结果。在合成中,使用了3,5-二取代-4-
异噁唑基
甲烷基作为类
固醇A环的前体。