[Cl:1][C:2]1[CH:3]=[C:4]([C:37]2[CH:42]=[CH:41][C:40]([F:43])=[CH:39][CH:38]=2)[CH:5]=[C:6]([Cl:36])[C:7]=1[CH2:8][C@@H:9]1[CH2:13][C@@H:12]([CH2:14][O:15]C(C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[O:11][C:10]1=[O:35].C(=O)(O)[O-].[Na+]>ClCCl.CO.Cl>[Cl:1][C:2]1[CH:3]=[C:4]([C:37]2[CH:38]=[CH:39][C:40]([F:43])=[CH:41][CH:42]=2)[CH:5]=[C:6]([Cl:36])[C:7]=1[CH2:8][C@@H:9]1[CH2:13][C@@H:12]([CH2:14][OH:15])[O:11][C:10]1=[O:35]Redissolve (3R,5S)-3-(3,5-Dichloro-4′-fluoro-biphenyl-4-ylmethyl)-5-trityloxymethyl-dihydro-furan-2-one in 30 mL of dichloromethane and 50 mL of methanol containing 0.5 mL of concentrate HCl. Stir the mixture overnight and neutralize with aqueous sodium bicarbonate. Most of the methanol and dichloromethane are removed. Extract the product with ethyl acetate. Wash the organic layers with water and then brine. Evaporate the solvent and chromatograph the product on flash silica gel using 5 to 25% acetone in methylene chloride. Evaporate the product containing fractions and recrystallize from ethyl acetate and heptane to afford 2.5 g (44% yield) of (3R,5S)-3-(3,5-dichloro-4′-fluoro-biphenyl-4-ylmethyl)-5-hydroxymethyl-dihydro-furan-2-one.
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