“…The residue was chromatographed on silica gel (hexane-EtOAc, 96:4) to obtain compound 6 (145.1 mg, 71%) as colorless oil. IR (neat) ν max / cm -1 : 2926, 2872, 1447, 1384, 1025, 873, 778, 599; 1 H NMR (CDCl 3 , 300 MHz) δ 0.71 (3H, s, 0.81 (3H, d, J 6.6 Hz,, 0.81 (3H, s, H-19), 1.00 -1.85 (15H, m), 2.00 -2.36 (2H, m), 2.79 (1H, dd, J 9.5; 11.0 Hz, 3.58 (1H, dd, J 2.4; 9.5 Hz, 6.24 (1H, brs, 7.19 (1H, brs, 7.34 (1H, brs,; 13 C NMR (CDCl 3 , 75.5 MHz) δ 11.2 (CH 2 , C-12), 13.9 (CH 3 , C-19), 16,8 (CH 3 -cleroda-15(16)-oxo-4(18),13(16),14-triene (7) AgF (101.2 mg, 0.8 mmol) was added to a solution of compound 6 (18.4 mg, 0.04 mmol) in dry pyridine (6.0 mL), and the reaction mixture was stirred for 23 h at room temperature under nitrogen. The crude product was filtered through a pad of Celite (5 cm) on silica gel using ethyl ether as eluent.…”