In order to clarify the stereochemistry at C-4 in enzymatic saturation of Δ4-3-ketoste-roids synthesis of 4-deuterated testosterone and androst-4-ene-3, 17-dione (XVIII, XIX) has been undertaken. The key intermediate leading to the required substrate, 4α-d1-5α-androstane-3β, 4β, 17β-triol 3, 17-bis (dimethyl-tert-butylsilyl) ether (XVI), was prepared by stereospecific reduction with lithium aluminum deuteride from 3β, 17β-dihydroxy-5α-androstan-4-one disilyl ether (XIII), which was readily obtainable from androst-4-ene-3β, 17β-diol disilyl ether (XI) by hydroboration, followed by oxidation with chromium trioxide-pyridine complex. Dehydration of XVI with phosphorus oxychloride in pyridine provided the Δ4 olefine (XVIIb) which on chromium trioxide oxidation was led to the desired compounds. Reductive dehalogenation of 4-bromotestosterone silyl ether (II) with lithium aluminum deuteride and subsequent oxidation with chromium trioxide-pyridine complex afforded 4-d1-testosterone silyl ether (VII) in which the deuterium incorporation, however, proved to be unsatisfactory.
为了弄清Δ4-3-
酮基类
固醇酶饱和合成 4-氚代
睾酮和雄甾-4-
烯-3,17-二
酮(XVIII,XIX)过程中 C-4 的立体
化学结构,我们进行了一项研究。所需底物 4α-d1-5α
雄甾烷-3β,4β,17β-三醇 3,17-双(二
甲基-叔丁基
硅基)醚(XVI)的关键
中间体是用
氘化
铝锂从 3β、17β-二羟基-5α-
雄甾烷-4-
酮二
硅基醚(XIII)的立体还原,然后用
三氧化铬-
吡啶络合物进行
氧化,制备了 3β,17β-二羟基-5α-
雄甾烷-4-
酮二
硅基醚(XVI)。XVI 在
吡啶中与
氧氯化
磷脱水后得到 Δ4
烯烃(XVIIb),再用
三氧化铬氧化后得到所需的化合物。用
氘化
铝锂对 4-
溴睾酮硅基醚 (II) 进行还原
脱卤反应,然后用
三氧化铬-
吡啶络合物进行
氧化,得到了 4-d
1-睾酮硅基醚 (VII)。