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

Participants

Reaction Steps

To Compound (49a) (43 mg, 0.088 mmol) dissolved in 3.0 ml of methanol was added 9 mg of palladium-carbon, and the mixture stirred under hydrogen atmosphere for 2 hours at room temperature. After the palladium-carbon was removed by filtration, the filtrate was concentrated under reduced pressure. The residue was purified by a preparative thin layer chromatography (Merck, Kieselgel 60 F254, 0.5 mm; chloroform:methanol=10:1) and further by crystallization from diethyl ether to give 32 mg (91%) of Compound (50a).

Provenance & Evidence