反应详情

This synthesis is depicted in FIG. 1. A solution of the methyl carbonate, 17β-methoxycarbonyloxy-5α-androstan-3-one (II) (9.6 g, 27.6 mmol) in toluene (200 ml) was pyrolyzed (b) in a Pyrex glass column (l=10 m, φ=9 mm) at 480° (N2 stream ca. 11 ml/min) at a rate of ca. 1 g/h. The crude product (collected in two liquid N2 -cooled traps) was washed with sat. aq. NaHCO3 - and NaCl-solution, dried (Na2SO4) and evaporated. The residue (7.24 g, 97%) was recrystallized from PE at 0° to give 6.42 g (87%) of 1. An analytical sample was recrystallized from acetonitrile at RT. M.p. 142°-144°, [a]D =+35.6° (c=1.15) ([2]: m.p. 140°-141°, [a]D17 =+38° (c=2.08)). - IR. (CDCl3): 1710s, 1595w. - 1H-NMR. (360 Mhz): 0.79 (s, 3 H); 1.05 (s, 3 H); 5.70 (m, 1 H); 5.84 (m, 1 H).

1. customat 480°
2. washThe crude product (collected in two liquid N2 -cooled traps) was washed with sat. aq. NaHCO3 - and NaCl-solution
3. dry with materialdried (Na2SO4)
4. customevaporated
5. customThe residue (7.24 g, 97%) was recrystallized from PE at 0°