Triethylamine → methyl (2S,4aR,6aR,7R,9S,10aS,10bR)-2-(furan-3-yl)-9-(methanesulfonamido)-6a,10b-dimethyl-4,10-dioxo-2,4a,5,6,7,8,9,10a-octahydro-1H-benzo[f]isochromene-7-carboxylate

Participants

Reaction Steps

A solution of 39 (0.10 g, 0.26 mmol), methanesulfonyl chloride (0.08 mL, 1.03 mmol), NEt3 (0.04 mL, 0.28 mmol) and a catalytic amount of DMAP in CH2Cl2 (50 mL) was stirred at room temperature for 2 h. The mixture was washed with 2N HCl (30 mL), 2N NaOH (30 mL), and H2O (30 mL) and dried (Na2SO4). Removal of the solvent under reduced pressure afforded a crude solid. The crude solid was purified by column chromatography (eluent: 2% MeOH/CH2Cl2) to afford 0.7 g (56%) of 42 as a white crystalline solid, mp 262-265° C. (EtOAc/n-hexanes); 1H NMR (CDCl3); δ 1.09 (3H, s); 1.46 (3H, s); 1.60 (3H, m); 1.79 (1H, dd, J=2.7, 9.6); 2.07 (2H, m); 2.18 (1H, m); 2.21 (1H, s); 2.50 (2H, m); 2.75 (1H, dd, J=3.6, 13.2); 2.99 (3H, s); 3.72 (3H, s); 4.15 (1H, m); 5.34 (1H, d, J=5.4); 5.55 (1H, dd, J=5.1, 11.4); 6.38 (1H, dd, J=0.9, 1.2); 7.41 (1H, dd, J=1.5, 1.8); 7.43 (1H, dd, J=0.9, 1.5).

Provenance & Evidence