Stepwise side-chain construction schemes leading to pregnane derivatives were tested in the 14β-androst-5-ene series. 6β-Methoxy-3α,5-cyclo-5α,14β-androstan-17-one (I) gave after methylenation and hydroboration the 17α-hydroxymethyl derivative III. Subsequent oxidation to the aldehyde VI, Grignard reaction with methylmagnesium iodide, and reoxidation led to the ketone VII and to the isomeric 17β-derivative VIII as a minor product. Final i-steroid cleavage of VII furnished the known 14β,17α-pregnenolone IX; the minor product VIII gave the 17β-isomer X. Alternatively, the ketone X was prepared from 6β-methoxy-3α,5-cyclo-5α,14β-androstan-17α-ol p-toluenesulfonate (XI) by cyanide substitution, diisobutylaluminum hydride reduction to the aldehyde XIV, and further as described for IX. The mass and NMR spectra of the four pregnenolone derivatives IX, X, XVIII, and XIX, isomeric in positions 14 and 17, were studied.
在14β-雄烯-5-烯系列中测试了逐步侧链构建方案,导致孕烷衍生物的产生。6β-甲氧基-3α,5-环-5α,14β-雄烷-17-酮(I)在甲基化和氢硼化后产生了17α-羟甲基衍生物III。随后氧化为醛VI,与甲基镁碘化物进行Grignard反应,再氧化得到酮VII和同分异构体17β-衍生物VIII(作为次要产物)。最终对酮VII进行i-类固醇裂解得到已知的14β,17α-孕酮IX;次要产物VIII得到17β-异构体X。另外,从6β-甲氧基-3α,5-环-5α,14β-雄烷-17α-醇p-甲苯磺酸盐(XI)通过氰化物取代、二异丁基铝氢化还原到醛XIV,再按照IX描述的步骤进行,制备了酮X。研究了位置14和17异构的四种孕酮衍生物IX、X、XVIII和XIX的质谱和NMR谱。