Methanol → Androsta-4,16-dien-3-one

Participants

Reaction Steps

This synthesis is depicted in FIG. 1. Several methods are known for the conversion of testosterone into Androsta-4,16-dien-3-one (Brooksbank et al, Biochem. J. (1950) AZ:36). Alternatively, thermolysis (460°) of the methyl carbonate of testosterone gives Androsta-4,16-dien-3-one in 90% yield. 17B-MethoxyCarbonyioxy-androst-4-en-3-one (IV) was prepared from testosterone (III. Fluka) with methyl chloroformate/pyridine (a) in 76% yield (after recrystallization from MeOH). M.p. 140-141°, [a]D =+95.4°(c=1.10) IR. (CDCl3):1740s, 1665s, 1450s, 1280s , 1H-NMR. (360 MHz):0.87 (s, 3H); 1.20 (s, 3H); 3.77 (s, 3H); 4.53 (br. t, J 8, 1H); 5.75 (s, 1H). A solution of the methyl carbonate IV in toluene was pyrolyzed (b) as described for I. Recrystallization of the crude product from acetone at RT. gave pure ketone 4 in 90% yield. M.p. 127-129.5°, (a)D +118.90°(C=1.32) ([3]:m.p. 131.5-133.5°(hexane), [a]D16 =+123±3.50°(C=1.03)). IR. (CDCl3):3050w, 1660s, 1615m. 1H-NMR. (360 MHz):0.82 (s, 3H); 1.22 (s, 3H); 5.70 (m, 1H); 5.73 (s, 1H); 5.84 (m, 1H).

Provenance & Evidence