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

Participants

Reaction Steps

To the above Compound (44) (300 mg, 0.50 mmol) dissolved in 10 ml of THF were added 1.0 ml of water and 270 mg (1.03 mmol) of triphenylphosphine. The mixture was heated to reflux for 24 hours. After the addition of ethyl acetate, it was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was loaded onto a silica gel column (silica gel 20 g), followed by elution with 60 ml of ethyl acetate to remove nonpolar fractions. The polar fractions eluted with 120 ml of ethyl acetate and 80 ml of chloroform-methanol (20:1) mixture were combined, and concentrated under reduced pressure. The residue was further purified by a column chromatography (Merck, Lobar column, size B; chloroform:methanol=20:1-10:1) to give 262 mg (83%) of Compound (45a) as a powdery material.

Provenance & Evidence