Triethylamine → HCID 18790053, compound

Participants

Reaction Conditions

Reaction Steps

A solution containing (-)-4-benzyl-3-(4-phenylsulfonylbutanoyl)oxazolidin-2-one (2 g, 5.16 mmol) in anhydrous CH2Cl2 (20 mL) is cooled to 0° C. Di-n-butylboron triflate (1 M in CH2Cl2, 6 mL, 6.03 mmol) is added by syringe over 15 minutes followed by the addition of triethylamine (0.68 g, 6.76 mmol). The clear yellow solution is then cooled to -78° C. Freshly distilled 5-phenylpentanal (0.92 g, 5.72 mmol) in anhydrous CH2Cl2 (2 mL) is added dropwise to the reaction mixture. After 30 min, the reaction mixture is warmed to 0° C. and maintained at this temperature for 1 hour. The reaction mixture is quenched by the slow addition of 3:1 MeOH/pH 7 phosphate buffer (30 mL) followed by 2:1 MeOH/30% H2O2 (30 mL) being careful to keep the temperature below 5° C. After the addition is complete, the reaction is maintained an additional hour at 0° C. then concentrated to half-volume in vacuo. The mixture is then diluted with diethyl ether (100 mL) and water (100 mL) and the layers are separated. The organic phase is washed with 5% NaHCO3 (3×50 mL), aqueous NaHSO3 (3×50 mL), water (50 mL), brine (50 mL), dried over anhydrous Na2SO4, filtered and concentrated. The crude product is combined with the crude material obtained from four additional reactions performed on identical scale and purified by silica gel chromatography (CH2Cl2 /diethyl ether, 19:1→9:1) to provide 4 g (35%) of (-)-4-benzyl-3-[3-hydroxy-7-phenyl-2-(2-phenylsulfonylethyl)-heptanoyl]-oxazolidin-2-one as a colorless, viscous oil which is homogeneous by TLC analysis [CH2Cl2 /diethyl ether, 19:1, Rf (oxazolidinone)=0.45, Rf (aldol product)=0.40]. [α]23D -20° (c 7.5, CHCl3); 1H NMR (300 MHz, CDCl3) δ 1.42-1.58 (m, 6H), 2.06 (m, 1H), 2.20 (m, 1H), 2.24 (d, J=4 Hz, 1H), 2.58 (t, J=7.5 Hz, 2H), 2.69 (dd, J=13.3, 9.9 Hz, 1H), 3.24 (m, 3H), 3.86 (m, 1H), 3.98 (quint. J=4.2 Hz, 1H), 4.16 (m, 2H), 4.65 (m, 1H), 7.18-7.52 (m, 10H), 7.59 (m, 2H), 7.68 (m, 1H), 7.90 (m, 2H) ppm. Mass spectrum (FAB) m/z 550 (M+H)+.

Provenance & Evidence