Reaction Steps
[α]D +47° (MeOH, c 1.55); UV λmax (ε) 240 (4571), 282 (2174), 290 (2177); IR (neat) νmax 3284, 2960, 1747, 1724, 1653, 1540, 1490, 1339, 1272, 1174 cm-1 ; EIMS m/z (rel intensity) 674/675/678 (47/35/8), 432/434/436 (11/5/2), 299/301/303 (39/30/7), 227 (64), 215/217/219 (31/20/8), 141 (100); high resolution EIMS m/z 674.21643 (calcd. for C34H4Cl2N2O8, -0.3 mmu error); 1H NMR (CDCl3) amino or hydroxyacid unit δ (carbon position, multiplicity; J in Hz) 7,8-epoxy-5-hydroxy--6-methyl-8-phenyl-2-octenoic acid (A) 5.77 (2, d; 15.4), 6.65 (3, ddd; 15.4, 9.3 and 6.0), 2.47 (4, dt; 14.2 and 10.2), 2.55 (4, br dd; 14.2 and 5.6), 5.13 (5, ddd; 11.0, 4.6 and 1.6), 1.81 (6, m), 1.15 (6-Me, d; 6.9), 2.93 (7, dd; 7.6 and 2.0), 3.7 (8, d; 2.0), 7.22-7.26 (10/14, m), 7.32-7.39 (11/12/13, m); 3,5-dichloro-4-hydroxyphenylalanine (B) 4.81 (2, m), 5.69 (2-NH, d; 8.6), 3.11 (3, dd; 14.5 and 5.6), 3.50 (3, dd; 14.3 and 7.0), 7.13 (5/9, s), 5.78 (7-OH, s); 3-amino-2-methylpropionic acid (C) 2.73 (2, m), 1.22 (2-Me, d; 7.1), 3.19 (3, dt; 13.4 and 6.9), 3.58 (3, ddd; 13.6, 5.8 and 4.1), 6.82 (3-NH, br t; 5.9); leucic acid (D) 4.84 (2, dd; 9.9 and 3.2), 1.38 (3, m), 1.68-1.75 (3, m), 1.68-1.75 (4, m), 0.86 (4-Me, d; 6.7), 0.87 (5, d; 6.7), 13C NMR (CDCl3) unit δ (carbon position) A 165.4 (1), 125.4 (2), 140.9 (3), 36.7 (4), 76.3 (5), 40.6 (6), 13.5 (6-Me), 63.0 (7), 58.9 (8), 136.7 (9), 125.6 (10/14), 128.7 (11/13), 128.6 (12), B 170.7 (1), 53.3 (2), 35.0 (3), 130.3 (4), 129.0 (5/9), 121.0 (6/8), 146.7 (7); C 175.3 (1), 38.4 (2), 13.9 (2-Me), 41.5 (3); D 170.8 (1), 71.3 (2), 39.4 (3), 24.6 (4), 21.3 (4-Me), 22.9 (5).
