Reaction Steps
To a cold solution (−78° C. bath) of (4S,5R)-5-[3,5-bis(trifluoromethyl)phenyl]-3-{[6′-methoxy-2″-methyl-4-(trifluoromethyl)-1,1′:3′,1″-terphenyl-2-yl]methyl}-4-methyl-1,3-oxazolidin-2-one (75 mg, 0.11 mmol) in dichloromethane (1 mL) was added boron tribromide (106.6 mg, 0.426 mmol). The resulting mixture was aged cold (−78° C. bath) for 1 hour then allowed to warm to ambient temperature overnight. Reaction was quenched with ice followed by extraction with dichloromethane. The combined extracts were washed with brine and then over Na2SO4. The resulting mixture was filtered and concentrated. The residue was purified by preparative TLC on SiO2 (eluted with 30% ethyl acetate in hexanes) to afford (4S,5R)-5-[3,5-bis(trifluoromethyl)phenyl]-3-{[6′-hydroxy-2″-methyl-4-(trifluoromethyl)-1,1′:3′,1″-terphenyl-2-yl]methyl}-4-methyl-1,3-oxazolidin-2-one. LCMS calc.=653.16; found=654.19 (M+1)+. 1H NMR signals are doubled because of atropoisomerism 1H NMR (CDCl3, 500 MHz) δ 7.87-7.84 (m, 1H), 7.76 (s, 0.5H), 7.72-7.65 (m, 2.5H), 7.63 (s, 1H), 7.53-7.47 (m, 1H), 7.33-7.23 (m, 3H), 7.23-7.16 (m, 2H), 7.12 (dd, J=10.5, 2.5 Hz, 1H), 7.04 (d, J=8.0 Hz, 0.5H), 7.02 (d, J=8.5 Hz, 0.5H), 5.64 (d, J=8.0 Hz, 0.5H), 5.32 (d, J=7.5 Hz, 0.5H), 4.98, 4.92 (d, J=16 Hz, 1H), 4.23 (d, J=15.5 Hz, 0.5H), 4.07 (d, J=15.5 Hz, 0.5H), 3.89-3.82 (m, 0.5H), 3.74-3.67 (m, 0.5H), 2.32, 2.28 (s, 3H), 0.58 (d, J=7 Hz, 1.5H), 0.49 (d, J=6.5 Hz, 1.5H).
