Reaction Steps
A mixture of 3β-acetoxy-17-chloro-16-formylandrosta-5,16-diene (Compound 3) (2.0 g, 5.23 mmol), 1H-1,2,3-triazole (552 mg, 7.98 mmol) and K2CO3 (2.20 g, 15.95 mmol) in dry DMF (40 ml) was heated at 80° C. under N2 atmosphere for 2 h. After cooling to room temperature, the reaction mixture was poured onto ice-water (400 ml), and the resulting precipitate was filtered, washed with water, and dried to give a dirty white solid. This was subjected to flash chromatography, and on elution with pet. ether/EtOAc/Et3N, (6.7:3:0.3), gave firstly 3β-acetoxy-17-(2H-1,2,3-triazol-2-yl)-16-formylandrosta-5,16-diene (Compound 15) (684 mg, 28%), mp 145-148° C. 1H NMR (300 MHz, CDCl3): δ 1.09 (3H, s, 18-Me), 1.26 (3H, s, 19-Me), 2.04 (3H, s, 3β,-OAc), 4.61 (1H, m, 3α-H), 5.42 (1H, d, J=4.2 Hz, 6-H), 7.85 (2H, s, 4′ and 5′-H) and 10.55 (1H, s, 16-CHO). Analysis calculated for C24H31O3N3: C, 70.37; H, 7.63; N, 10.27. Found: C, 70.30; H, 7.95; N, 9.87. Further elution with pet. ether/EtOAc/Et3N, (6:4:0.3) gave 3β-acetoxy-17-(1H-1,2,3-triazol-1-yl) -16-formylandrosta-5,16-diene (Compound 16) (1.48 g, 62%), mp 215-217° C. 1H NMR (300 MHz, CDCl3): δ 1.08 (3H, s, 18-Me), 1.18 (3H, s, 19-Me), 2.04 (3H, s, 3β-OAc), 4.63 (1H, m, 3α-H), 5.43 (1H, d, J=4.2 Hz, 6-H), 7.85 (2H, s, 4′ and 5′-H) and 9.94 (1H, s, 16-CHO). Analysis calculated for C24H31O3N3: C, 70.37; H, 7.63; N, 10.27. Found: C, 70.37; H, 7.86; N, 10.10.
