Biomimetic total synthesis of steroids VI. Stereospecific synthesis of 19-nor-8α-steroids and 11α-alkyl derivatives
作者:M. B. Groen、B. Hindriksen、F. J. Zeelen
DOI:10.1002/recl.19821010404
日期:——
stereospecificity. Cyclization of similar substrates with an alkyl substituent in the appropriate position gave exclusively 11α-alkyl derivatives of 8a and 9a. The products were converted into the corresponding 13α,17α-epoxides by peracid oxidation and hence into derivatives of 8α-estrone and 8α-estradiol. 11α-Methyl-8α-estra-1,3,5(10)-triene-3,17(3-diol (16b) was obtained in its two enantiomeric forms
2- [6-(3-甲氧基苯基)-(Z)-3-己烯基] -3-甲基-2-环戊烯醇(7a)的阳离子环化生成1-和3-甲氧基-17-甲基-8α-gona-1 ,3,5(10),13(17)-四烯(8a和9a)具有完全的立体特异性。在适当位置具有烷基取代基的类似底物的环化仅产生8a和9a的11α-烷基衍生物。通过过酸氧化将产物转化为相应的13α,17α-环氧化物,因此转化为8α-雌酮和8α-雌二醇的衍生物。通过其3-甲基醚的拆分,以其两种对映体形式获得11α-甲基-8α-estra-1,3,5(10)-三烯-3,17(3-二醇(16b))。