Synthesis of Steroidal Indoxyl, and Derivatives from 3-ketosteroid

Abstract

5&alpha-Androstan-17&beta-ol-3-one condenses with 2-nitrobenzaldehyde in alkaline conditions to give the steroidal indoxyl 17&beta-hydroxy-1-(3′-oxoindan-2′-yliden)-3-nor-1,2-secoandrostan-3-oic acid (I) which on refluxing with acetic anhydride affords the lactam 17&beta-acetoxy-3′-aza-4a-homoandrost-1-eno-(3,2-a)-indan-3′,4-dione (II). Reduction of I with sodium borohydride gives the indole 17&beta-hydroxy-1-(indol-2′-yl)-3-nor-1, 2-secoandrostan-3-oic acid (III). The results of this synthesis suggest that 3-ketosteroids saturated in ring A react in a similar manner to 17-ketosteroids, with 2-nitrobenzaldehyde.