p-Toluenesulfonic acid → 3-(Benzyloxy)estra-1,3,5(10),15-tetraen-17-one

Participants

Reaction Steps

A solution of 1.04 g (2.57 mmol) of 43, 117 mg (0.617 mmol) of pTsOH in acetone (70.3 mL) and H2O (11.4 mL) was stirred at rt for 1.5 h. The reaction mixture was adjusted to pH 7 with 5% NaHCO3 and concentrated by rotovap to about 30 mL without heating. The solution was poured into H2O (50 mL) and extracted with EtOAc (3×, 70 mL). Combined organic extracts were dried over Na2SO4 and concentrated in vacuo giving a white solid. Crystallization of the residue from CH2Cl2/hexanes gave 477 g (52%) of 44 as fine white needles. Data for 44: TLC, T-1, Rf 0.5; 1H NMR (400 MHz, CDCl3) δ 1.12 (s, 3H, H-18), 5.05 (s, 2H, benzylic-H), 6.10 (dd, 1H, J=5.9, 3.2 Hz, H-15), 6.76 (d, 1H, J=2.7 Hz, H-4), 6.81 (dd, 1H, J=8.6, 2.7 Hz, H-2), 7.22 (d, 1H, J=8.6 Hz, H-1), 7.31–7.45 (m, 5H, Ar—H), 7.64 (dd, 1H, J=5.9, 1.1 Hz, H-16).

Provenance & Evidence