Sodium Chloride → HCID 24875829, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of benzyl 7-[(1R,2R,3R)-2-(4,4-difluoro-3-oxooctyl)-5-oxo-3-(2-tetrahydropyranyloxy)cyclopentyl]heptanate (19) (70.49 g, 124.8 mmol) in acetonitrile (705 ml), water (70.5 ml) and 85% phosphoric acid (70.5 ml) were added and the mixture was stirred for 3 hours at approximately 20° C. The solution was supplemented with 10% aqueous sodium chloride (705 ml), and extracted three times with ethyl acetate (276 ml). The organic layers were combined and sequentially washed with 10% aqueous sodium chloride (360 ml), saturated sodium bicarbonate water (360 ml) and saturated aqueous sodium chloride (360 ml). The solution was dried with anhydrous magnesium sulfate (51 g) and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (Fuji Silysia BW-300: 2100 g; ethyl acetate:hexane =1:4). The fractions containing impurities were re-purified by silica gel column chromatography (Fuji Silysia BW-300 1000 g, ethyl acetate:hexane =1:4) to give benzyl 7-[(2R,4aR,5R,7aR)-2-(1,1-difluoropentyl)-2-hydroxy-6-oxooctahydro cyclopenta[b]pyran-5-yl]heptanate (20) (52.64 g; 109.5 mmol; yield: 87.8%) as a colorless oil.

Provenance & Evidence