Water → 3-Methylandrost-5-en-17-one

Participants

Reaction Steps

The 3β-methylandrost-5-en-17-one 17-ethylene ketal (13) (2.20 g 6.7 mmol) was dissolved in acetone (100 ml). p-Toluenesulfonic acid (100 mg) and H2O (20 ml) were added and the solution was refluxed for 2 hours. The solution was evaporated, taken up in ether (30 ml), washed with saturated NaHCO3, H2O, and then dried over MgSO4. The solution was filtered and evaporated to give a colorless solid which was recrystallized from methanol to give 3β-methylandrost-5-en-17-one (14) as colorless plates, 1.17 g (61%) mp 148°-150° C.; IR(KBr) 3010, 2910, 1740, 1455, 1430, 1365 cm-1 ; 1H NMR (CDCl3) δ5.41 (brd, J=6Hz, 1H, H-6), 1.11 (s, 3H, C-19 Me), 0.99 (s, 3H, C-18 Me), 1.07 (d, 3H, C-3 Me); MS (m/e) 286 (M+, 58), 271 (51), 229 (31), 159 (36), 105 (72), 9- (95), 79 (89), 55 (9), 41 (100).

Provenance & Evidence