The present invention discloses a process for the preparation of 16, 17-acetals of pregnane derivatives having formula (I) wherein each substituent is independently selected from; R1 is H or CH3; R2 is C1-C6 linear or branched alkyl, alkynyl group or cycloalkyl group; aryl or heteroaryl group; or R1 and R2 combine to form saturated, unsaturated C3-C6 cyclic or heterocyclic ring; R3 and R4 are same or different and each independently represents H or halogen; R5 is -OH or –OCOR wherein R represents H or C1-C6 linear, branched or cyclic alkyl group that may be substituted.
                            本发明揭示了一种制备16,17-孕烷衍
生物的16,17-
缩醛的方法,其具有式(I)的结构,其中每个取代基独立地选择自; R1为H或
CH3; R2为C1-C6直链或支链烷基,炔基或环烷基; 芳基或杂环芳基; 或R1和R2结合形成饱和的、不饱和的C3-C6环或杂环环; R3和R4相同或不同,每个独立地表示H或卤素; R5为-OH或-OCOR,其中R表示H或C1-C6直链、支链或环烷基,可能被取代。