Methanol → (3S,4aR,4bS,6S,8R,8aR,10aR)-3-Furan-3-yl-6-isobutyryloxy-4a,8a-dimethyl-1,5-dioxo-dodecahydro-2-oxa-phenanthrene-8-carboxylic acid methyl ester

Participants

Reaction Steps

A solution of 39 (0.10 g, 0.26 mmol), benzoyl chloride (0.11 g, 0.78 mmol) and DMAP (0.08 g, 0.78 mmol) in CH2Cl2 (20 mL) was stirred at room temperature for 2 h. Absolute MeOH (15 mL) was added and the solvent was removed under reduced pressure. CH2Cl2 (25 mL) was added to the residue and the solution was washed with 10% HCl (2×20 mL), H2O (3×20 mL), and saturated NaCl (3×20 mL) and dried (Na2SO4). Removal of the solvent under reduced pressure afforded 0.09 g (67%) of 10 as a white crystalline solid, mp 155-157° C. (EtOAc/n-hexanes); 1H NMR (CDCl3): δ 1.44 (3H, s); 1.50 (3H, s); 1.63 (3H, m); 1.82 (1H, dd, J=2.1, 10.5); 2.0 (1H, m); 2.12 (1H, dd, J=2.7, 8.4); 2.17 (1H, m); 2.32 (1H, s); 2.48 (1H, dd, J=5.4, 13.2); 2.79 (1H, dd, J=3.3, 6.9); 2.87 (1H, dd, J=2.7, 13.5); 3.71 (3H, s); 4.69 (1H, m); 5.55 (1H, dd, J=5.1, 11.4); 6.37 (1H, dd, J=0.9, 1.8); 7.1 (1H, d, J=6.0); 7.39 (1H, t, J=1.8); 7.41 (1H, dd, J=0.9, 1.8); 7.46 (1H, m); 7.53 (1H, tt, J=1.5, 2.7, 7.2); 7.80 (1H, t, J=2.4); 7.82 (1H, t, J=1.2.

Provenance & Evidence