Pellicciari R, Natalini B, Fringuelli R
Istituto di Chimica Farmaceutica e Tecnica Farmaceutica, Università degli Studi, Perugia, Italy.
Steroids. 1987 Apr-May;49(4-5):433-41. doi: 10.1016/0039-128x(87)90016-x.
alpha-Diazo-beta-hydroxy esters 3, obtained by condensation of ketones 1 with ethyl diazo(lithio)acetate 2, are efficiently converted into the corresponding beta-ketoesters 4 by exposure to dirhodium (II) tetraacetate. Application of this two-step sequence to 3 beta-acetoxy-5-androstene-17-one 5b and to 3-acetoxy estrone 10b afforded regiospecifically and in very high overall yield the corresponding ethyl 17a-oxo-D-homo-steroid-17-carboxylates 7a,b and 12a,b, which were decarboalkoxylated to give, respectively, 3 beta-hydroxy-D-homo-5-androstene-17a-one 8 and D-homoestrone 13.
通过酮1与重氮（锂）乙酸乙酯2缩合得到的α-重氮-β-羟基酯3，经暴露于四乙酸二铑（II）可有效地转化为相应的β-酮酯4。将此两步反应序列应用于3β-乙酰氧基-5-雄甾烯-17-酮5b和3-乙酰氧基雌酮10b，区域选择性地且以非常高的总收率得到相应的17α-氧代-D-高甾族化合物-17-羧酸乙酯7a、b和12a、b，将它们进行脱羰烷氧基化反应分别得到3β-羟基-D-高-5-雄甾烯-17α-酮8和D-高雌酮13。
