Lithium hydroxide, monohydrate → methyl 7-[(1R,2R,3R,5S)-5-acetoxy-2-((E)-4,4-difluoro-3-oxo-4-phenyl-1-butenyl)-3-(2-tetrahydropyranyloxy)cyclopentyl]heptanate

Participants

Reaction Steps

To a solution of dimethyl (3,3-difluoro-2-oxo-3-phenylpropyl)phosphonate (6) (0.262 g, 0.942 mmol) in t-butyl methyl ether (7 ml), lithium hydroxide monohydrate (38.2 mg, 0.910 mmol) was added and the mixture was stirred for one hour at room temperature. A solution of methyl 7-[(1R,2R,3R,5S)-5-acetoxy-2-formyl-3-(2-tetrahydropyranyl-oxy)cyclopentyl]heptanate (2) (0.250 g, 0.627 mmol) in t-butyl methyl ether (3 ml) and water (0.3 ml) were added thereto, and the mixed solution was heat refluxed for approximately 48 hours. After cooling to room temperature, the reaction mixture was added to water, and extracted twice with t-butyl methyl ether. The organic layers were combined, sequentially washed with water, saturated sodium bicarbonate water and saturated aqueous sodium chloride, and then dried with anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was purified by silica gel column chromatography (Merck Art. 9385: 200 g; ethyl acetate:hexane=2:3). The fractions containing impurities were re-purified by silica gel column chromatography (Merck Art. 9385: 120 g; ethyl acetate:hexane=2:3), to give methyl 7-[(1R,2R,3R,5S)-5-acetoxy-2-((E)-4,4-difluoro-3-oxo-4-phenyl-1-butenyl)-3-(2-tetrahydropyranyloxy)cyclopentyl]heptanate (7) (0.257 g; 0.467 mmol; yield: 74.4%) as a colorless oil.

Provenance & Evidence