Synthesis of Steroidal Indoxyl, and Derivatives from 3-Ketosteroid

Abstract

5-Androstan-17-ol-3-one condenses with 2-nitrobenzaldehyde in alkaline conditions to give the steroidal indoxyl 17-hydroxy-1-(3′-oxoindan-2′-yliden)-3nor-1,2-secoandrostan-3-oic acid (I) which on refluxing with acetic anhydride affords the lactam 17-acetoxy-3′-aza-4a-homoandrost-1-eno-(3,2-a)-indan-3′,4dione (II). Reduction of I with sodium borohydride gives the indole 17-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 17ketosteroids, with 2-nitrobenzaldehyde.