(R)-Methyl 5-(2,2-dimethylcyclopentyl)-2-fluoro-4-hydroxybenzoate or (S)-methyl 5-(2,2-dimethylcyclopentyl)-2-fluoro-4-hydroxybenzoate (66.44AA or 66.44AB). A mixture of Rh(COD)2BF4 (Stem Chemical) 35138-22-8, 36.95 mg, 0.091 mmol) and (R)-1-[(S)-2-(R)-(Ditertbutylphosphino)ferrocenyl]ethyl-bis-(3,5-bistrifluoromethylphenyl)phosphine (Solvias, SL-J210-1, 81.5 mg, 0.100 mmol), was stirred in THF (75 mL) under N2 for 60 minutes and a dark red solution formed. To the resulting solution was added 66.43E (8.2 g, 45.4 mmol) and TEA (10 mol %, 0.63 mL, 4.54 mmol). The resulting solution was filled with H2 (200 psi) three times and stirred at room temperature under 200 psi H2 for 2 hours. The resulting mixture was passed through a short plug of silica gel, eluting with 1:1 hexane/EtOAc and then concentrated affording the desired product as a white solid (83% yield (6.8 g), 99.3% ee). The other enantiomer may be obtained as the majority product using the enantiomer of the ferrocenyl compound.
