Reaction Steps
(2R,S,3S) N2-(4-Benzylimidazole-2-carbonyl)-N-(tetrahydro-2-benzyloxy-5-oxo-3-furanyl)-L-alaninamide (17b), was isolated (75%) as a pale yellow glass: IR (KBr) 3294, 3031, 2937, 1792, 1650, 1530, 1453, 1444, 1119; 1H NMR(CDCl3) δ 7.99 (brm), 7.75 (brd), 7.36-7.11 (10H, m), 6.81 (1H, s), 5.51, 5.45 (d, s, J=5.3), 4.85-4.47 (4H, m), 3.95 (2H, s), 3.04-2.72 (1H, m), 2.48-2.35 (1H, m), 1.44 (d, J=6.9), 1.43 (d, J=7.1). (2R,S,3S) N2-[4-(2-Phenylethyl)imidazole-2-carbonyl]-N-(tetrahydro-2-benzyloxy-5-oxo-3-furanyl)-L-alaninamide (17c), was isolated (79%) as a pale yellow glass: IR (KBr) 3292, 3029, 2936, 1793, 1650, 1530, 1453, 1444, 1119; 1H NMR(CDCl3) δ 8.06 (brm), 7.70 (brs), 7.39-7.15 (10H, m), 6.82 (s), 6.81 (s), 5.53 (d, J=5.2), 5.48 (s), 4.87-4.53 (4H, m), 2.95 (4H, m), 3.11-2.37 (2H, m), 1.48 (d, J=5.6), 1.45 (d, J=6.7). (2R,S,3S) 1-[4-(2-Phenylethyl)imidazole-2-carbonyl]-N-(tetrahydro-2-benzyloxy-5-oxo-3-furanyl)-L-prolinamide (18c), was isolated (79%) as a pale yellow glass: IR (CH2Cl2) 3422, 2959, 1795, 1685, 1611, 1497, 1116;
