反应详情

According to the general procedure, a solution of ethyl 3-(4-methoxyphenyl)-2-methylacrylate (30 mg, 0.14 mmol) and iridium catalyst (S)-32 (4.5 mg, 0.0029 mmol, 2.0 mol %) in CH2Cl2 (1.4 mL) was hydrogenated. Removal of the solvent in vacuo and standard purification gave 37 (30 mg, 96%) as a colorless oil. [α]20D +24.5 (c 1.25, CHCl3); CSP HPLC analysis (Chiralcel OB-H; eluent: 99.5:0.5 hexanes/i-PrOH, 0.5 mL/min) determined a 90:10 er (80% ee) [tR(minor) 9.01 min, tR(major) 9.76 min]; 1H NMR (300 MHz, CDCl3) 7.08 (d, 2H, J=8.7 Hz), 6.81 (d, 2H, J=8.7 Hz), 4.09 (q, 2H, J=7.2 Hz), 3.78 (s, 3H), 3.01-2.90 (m 1H), 2.73-2.57 (m, 2H), 1.19 (t, 3H, J=7.2 Hz), 1.13 (d, 3H, J=6.6 Hz) ppm; 13C NMR (75 MHz, CDCl3) 176.2, 158.1, 131.4, 129.9, 113.7, 60.2, 55.2, 41.7, 38.8, 16.7, 14.2 ppm.

1. customRemoval of the solvent
2. customin vacuo and standard purification