| Abstract: | Partial Syntheses of Cardenolides and Cardenolide Analogues. VII. Synthesis of A/B-cis- and C/D-cis-linked Steroidal Mono- and Bis (α-methylene-γ-butyrolactones) The synthesis of A/B-cis- and C/D-cis-linked steroidal mono- and bis(α-methylene-γ-butyrolactones) 10–13 , 18 and 24 by Reformatsky-type reaction of 3β-acetoxy-14-hydroxy-5β, 14β-androstan-17-one( 6 ), 14-hydroxy-5β, 14β-androstane-3,17-dione ( 8 ), 3β-acetoxy-14-hydroxy-5β,14β-pregnan-20-one ( 17 ) and 14-hydroxy-5β,14β-pregnane-3,20-dione ( 23 ), respectively, with ethyl α-(bromomethyl)acrylate is described. All steroidal lactones exhibit strong inhibitory activity on the proliferation of Ehrlich ascites carcinoma cells in suspension culture. For inhibitory activity the lactone moiety at C-17 of the steroid molecule is more important than the lactone moiety at C–3 and C–20, respectively. |
