Sodium borohydride → HCID 22820392, compound

Participants

Reaction Steps

According to 1(b), 20.2 g of 16α-ethyl-3-methoxy-1,3,5(10)-estratrien-17-one, N,N-dimethylhydrazone, m.p. 101°-103° C. (from acetonitrile) is obtained from 20.4 g of 3-methoxy-1,3,5(10)-estratrien-17-one N,N-dimethylhydrazone after metallization and alkylation with 9.2 ml of bromoethane. By reaction with CuCl2.2H2O according to 1(c), the 17-ketone is obtained from the hydroazone and then, by reduction of the 17-ketone with sodium borohydride according to 1(d), 16.0 g of 16α-ethyl-3-methoxy-1,3,5(10)-estratrien-17β-ol, m.p. 75°-76° C. (from methanol) is prepared. 10.0 g of 16α-ethyl-3-methoxy-1,3,5(10)-estratrien-17β-ol is subjected analogously to 1(e) in succession to Birch reduction, acid hydrolysis, and reaction with pyridine hydrobromide perbromide, thus obtaining 7.8 g of 16α-ethyl-17β-hydroxy-4,9(10)-estradien-3-one, m.p. 132°-135° C. (from ethyl acetate/diisopropyl ether). This product is converted analogously to 1(f) with acetic anhydride/pyridine into the 17-acetate, m.p. 124°-126° C. (from ether) and analogously to 1(g) by ketalization and subsequent ketal cleavage into the 17β-acetoxy-16α-ethyl-5(10),9(11)-estradien-3-one.

Provenance & Evidence