Water → (6aR,7S,9aS,11R,12S,13aS)-5-benzyloxy-2-(t-butoxycarbonyl)-2,3,6, 6a,7,8,9,9a,10,11,12,13-dodecahydro-11-hydroxy-6a,7,10,10-tetramethyl-12-(4-nitrophenylsulfonyl)oxy-3-oxo-1H-benzo[8,8a][l]-benzopyrano[2,3-e]isoindole

Participants

Reaction Steps

To a solution of Compound (48a) (200 mg, 0.34 mmol) in 15 ml of dichloromethane were added 83 mg (0.68 mmol) of dimethylaminopyridine and 112 mg (0.51 mmol) of p-nitrobenzenesulfonyl chloride under ice-cooling, and the mixture stirred for 6 hours at the same temperature. After addition of water, the reaction mixture was extracted with ethyl acetate. The extract was washed sequentially with 1N HCl, water, an aqueous saturated sodium hydrogen carbonate solution, and water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by a column chromatography (Merck, Lobar column, size B; toluene:ethyl acetate=4:1) to give 184 mg (70%) of Compound (48f).

Provenance & Evidence