反应详情

Firstly an example of catalytic hydrogenation for the synthesis of 5α-androstanes from androst-5-enes is the synthesis of 3β-methyl-5α-androstan-17-one 2 from 3β-methylandrost-5-en-17-one 1. 3β-Methylandrost-5-en-17-one 1 (400 mg), prepared as described previously was dissolved in glacial acetic acid (80 ml). Palladium on carbon (10%, 100 mg) was added and the solution maintained under an atmosphere of hydrogen. When hydrogen uptake ceased, the solution was filtered through celite and evaporated to give solid which was recrystallized from methanol to yield 3β-methyl-5α-androstan-17-one, 2, (320 mg, 80% yield). MP 107°-108° C., 1H NMR (CDCl3) δ 0.86 (d, 3H, J-5 Hz, methyl at C-3), 0.85 (s, 3H, C-19 Me), 0.79 (s, 3H, C-18 Me).

1. temperaturethe solution maintained under an atmosphere of hydrogen
2. filtrationthe solution was filtered through celite
3. customevaporated
4. customto give solid which
5. customwas recrystallized from methanol