Reaction Steps
20% Pd(OH)2 --C (Pearlman's catalyst, Aldrich; 0.33 g) was added to a solution of (2S*,3S*,4R*,5R*)-1-benzyloxycarbonyl-4-benzyloxymethyl-3-[N-(5-isopropyl-2-methoxybenzyl)amino]-5-methyl-2-phenylpyrrolidine(0.61 g,1.03 mmol) and HCO2NH4 (0.39 g, 6.18 mmol) in MeOH (20 ml). The mixture was stirred and heated at a gentle reflux for 30 minutes. The catalysts were filtered off by the aid of a Celite pad, and washed with MeOH. The combined filtrate and washings were concentrated in vacuo. To the residue was added 1M NaOH aq. solution until the mixture became basic (pH 10-11). This was extracted with CH2Cl2 (×4). The combined CH2Cl2 extracts were washed with sat. NaCl aq. solution (×1), dried (K2CO3), and concentrated in vacuo to give a pale yellow oil (0.47 g). This was chromatographed over SiO2 (Merck Kieselgel 60, 7.0 g). Elution with CH2Cl2 --MeOH (300:1→200:1→100→60:1→50:1) gave title compound (0.40 g, 85%) as a pale yellow viscous oil: IRmax (film): 3340(w), 1610(m), 1498(s), 1250(s), 1110(s), 810(m), 738(s), 700(s) cm1 ; 1H-NMR δ: 7.43-7.20(m, 10H), 7.01(dd, J=8.4, 2.2 Hz, 1H), 6.82(d, J=2.2 Hz, 1H), 6.65(d, J=8.4 Hz, 1H), 4.56(s, 2H), 4.20(d, J=5.5 Hz, 1H), 3.67(d, J=13.6 Hz, 1H), 3.493(dd, J=9.3, 6.2 Hz, 1H), 3,489(s, 3H), 3.57(dd, J=9.3, 6.4 Hz, 1H), 3.42(d, J=13.6 Hz, 1H), 3.13(dd, J=5.5, 2.6 Hz, 1H), 3.06(dq, J=6.2, 6.2 Hz, 1H), 2.74(sep, J=7.0 Hz, 1H), 2.17-1.85(m, 3H), 1.42(d, J=6.2 Hz, 3H), 1.16(d, J=7.0 Hz, 6H) ppm.
