Sodium hydride → (6aR,7S,9aS,11S,13aS)-2-(t-butoxycarbonyl)-2,3,6,6a,7,8,9,9a, 10,11,12,13-dodecahydro-11-hydroxy-6a,7,10,10-tetramethyl-3-oxo-5-diphenoxyphosphinyloxy-1H-benzo[8,8a][1]benzopyrano[2,3-e]isoindole

Participants

Reaction Steps

Under nitrogen, 40 mg (1.0 mmol) of sodium hydride (ca. 60% in oil) was added to a solution of the above Compound (55a) (234 mg, 0.48 mmol) in 2 ml of dry dimethylformamide, and the mixture stirred for 15 min. To the reaction mixture was added dropwise 120 μl (0.58 mmol) of diphenyl phosphorochloridate, and the mixture stirred for another 1.5 hours at the same temperature. After addition of ice-water under ice-cooling, the reaction mixture was extracted with ethyl acetate. The extract was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by a column chromatography (silica gel 15 g; n-hexane:ethyl acetate=2:1) to give 277 mg (80%) of Compound (56a) as an oily material.

Provenance & Evidence