Synthesis of some D-homo-D-aza estratriene derivatives

In this paper two synthetic routes for obtaining D-homo-D-aza estratriene derivatives were described. Namely, starting from 3-methoxyestra-1,3,5(10)-trien-16-oximino-17-one (1) 3-methoxy-17-aza-D-homoestra-1,3,5(10)-triene (5) was synthesized in two step. Another D-aza derivative was synthesize, starting from 3-methoxy-17-oxo-16,17-secoestra-1,3,5(10)-trien-16-nitrile (6). For that purpose, the seco-cyanoaldehyde was converted into its 17-ethylenacetal 7 followed by subsequent reduction of the nitrile function with sodium borohydride in the presence of cobalt chloride hexahydrate. Finally, under acidic conditions the obtained 16-amino-17-ethylenacetal 8 was transformed into 3-metoxy-17-aza-D-homoestra-1,3,5(10),17(17a)-tetraene (9).