Sodium Hydroxide → HCID 15454894, compound

Participants

Reaction Steps

To a stirred solution of (2S*,3S*,4R*,5R*)-3-amino-1-benzyloxycarbonyl-4-methoxycarbonyl-5-methyl-2-phenylpyrrolidine (0.93 g, 2.52 mmol) in dry CH2Cl2 (20 ml) was added a solution of 5-isopropyl-2-methoxybenzaldehyde (0.56 g, 3.15 mmol) in dry CH2Cl2 (5 ml) at room temperature. To this was added NaBH(OAc)3 (0.80 g, 3.78 mmol) portionwise at room temperature. The added NaBH(OAc)3 dissolved gradually with stirring at room temperature. After stirring for 1.5 hours at room temperature, the reaction mixture was basified to pH 10-11 by adding 10% NaOH aq. solution with ice-cooling. The layers were separated, and the aqueous layer was extracted with CHCl3 (×3). The combined CH2Cl2 layer and CHCl3 extracts were washed with sat. NaCl aq. solution (×1), dried (Na2SO4 --K2CO3), and concentrated in vacuo to give a yellow viscous oil (1.69 g). This was chromatographed over SiO2 (Merck Kieselgel 60, 20 g). Elution with n-hexane-AcOEt (30: 1) followed by CH2Cl2 --MeOH (200:1) gave title compound (1.36 g, quant.) as a pale yellow viscous oil: IRmax (film): 3350(w), 1735(s), 1700(vs), 1487(s), 1290(s), 1250(s), 1030(s), 810(s), 735(s), 700(s) cm-1 ; 1H-NMR δ: 7.50-7.15(m, 10H), 7.03(dd, J=8.4, 2.2 Hz, 1H), 6.96(d, J=2.2 Hz, 1H), 6.70(d, J=8.4 Hz, 1H), 5.15(br.d, J=7.7 Hz, 1H), 5.03(br.s, 2H), 4.22-4.06(m, 1H), 3.84-3.58(m, 3H), 3.71(s, 3H), 3.64(s, 3H), 2.90-2.58 (m, 2H), 1.61(br.d, J=5.5 Hz, 3H), 1.19(d, J=7.0 Hz, 6H) ppm.

Provenance & Evidence