HCID 68704917, compound → Cyclopenta[c][1]benzopyran-8-ol, 2,2-difluoro-1,2,3,3a,4,9b-hexahydro-4-(4-hydroxyphenyl)-, (3aS,4R,9bR)-

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Reaction Steps

Stir a solution of difluorocyclopentane 29 (196 mg, 0.480 mmol) in 7 mL of THF and 3 mL of 3 M HCl overnight. Add 1 mL of 5 M HCl and let stir overnight. Dilute the solution with EtOAc. Separate the aqueous solution and extract 2× with EtOAc. The combined organic solutions were washed with saturated aqueous sodium bicarbonate, brine, dried over Na2SO4, filtered, and concentrated. Absorb to 2 g of silica gel and purify by silica gel chromatography (10 g silica gel, 10 to 60% EtOAc/Hexanes over 30 min at 35 mL/min) to give 155 mg (0.48 mmol, 100%) of difluorocyclopentane 30. The enantiomers were separated by preparative chiral chromatography (Chiralpak AD, 65/35 heptane/ethanol).

Provenance & Evidence