Synthesis and structure of 4′,4′-dimethyl[16α,17α]spiropentanopregn-4-ene-3,20-dione
作者:I. S. Levina、L. E. Kulikova、E. V. Shulishov、I. P. Klimenko、A. V. Kamernitskii、Yu. V. Tomilov
DOI:10.1007/s11172-006-0560-0
日期:2006.11
4′,4′-Dimethyl[16α,17α]spiropentanopregn-4-ene-3,20-dione was synthesized. The addition of diazo-2,2-dimethylcyclopropane generated from N-(2,2-dimethylcyclopropyl)-N-nitrosourea to 16,17-didehydropregnenolone acetate occurs regio-and stereospecifically to give 3β-acetoxy-1′,1′-dimethyl-20-oxopregn-5-ene-[16α,17α;7′,6′]-4′, 5′-diazaspiro[2.4]-hept-4′-ene in high yield. Its thermolysis affords a spiropentane-containing steroid, which is transformed into the target diketone. The anti position of the gem-dimethyl group in the fused spiropentane fragment is evident from the X-ray diffraction study of the final product.
合成了 4′,4′-二甲基[16α,17α]螺戊烷-4-孕甾-3,20-烯二酮。由 N-(2,2-二甲基环丙基)-N-亚硝基脲生成的重氮-2,2-二甲基环丙烷与 16,17-二去氢孕甾烯醇酮醋酸酯发生回归和立体定向加成,得到 3β-乙酰氧基-1′,1′-二甲基-20-氧代孕甾-5-烯-[16α,17α;7′,6′]-4′,5′-二氮杂螺[2.4]-庚-4′-烯的高产率。其热解产物是一种含螺戊烷的类固醇,该类固醇可转化为目标二酮。从最终产物的 X 射线衍射研究中可以明显看出,在融合的螺戊烷片段中,gem-二甲基基团的反位置。