Acetic Acid → methyl 7-[(1R,2R,3R,5S)-5-acetoxy-2-((6S)-4,4-difluoro-6-methyl-3-hydroxyoctyl)-3-(2-tetrahydropyranyloxy)cyclopentyl]heptanate

Participants

Reaction Steps

A solution of methyl 7-[(1R,2R,3R,5S)-5-acetoxy-2-((6S)-4,4-difluoro-6-methyl-3-oxooctyl)-3-(2-tetrahydro pyranyloxy)cyclopentyl]heptanate (D) (72.56 g, 132.7=1) in methanol (290 ml) was cooled to approximately −20° C., and sodium borohydride (5.00 g, 132.2 mmol) was added thereto. After stirring for approximately 35 minutes, acetic acid (7.5 ml, 131=1) was added dropwise, and the reaction mixture was concentrated under reduced pressure. The residue was supplemented with water (326 ml) and extracted three times with ethyl acetate (226 ml). The organic layers were combined, washed with 3% aqueous sodium chloride (323 ml) and saturated aqueous sodium chloride (323 ml), and dried with anhydrous magnesium sulfate (40.6 g). The solution was concentrated under reduced pressure to give methyl 7-[(1R,2R,3R,5S)-5-acetoxy-2-((6S)-4,4-difluoro-6-methyl-3-hydroxyoctyl)-3-(2-tetrahydropyranyloxy)cyclopentyl]heptanate (E) (73.01 g; quantitative yield) as a colorless oil.

Provenance & Evidence