Reaction Steps
To a stirred solution of 9 (496 mg, 0.9 mmol) in a mixture dichloromethane-methanol (2:1, 9 ml) at 0° C. the solution of diazomethane in diethyl ether was added until a yellow coloration persisted. After standing at room temperature for 1 h, the excess diazomethane was decomposed with acetic acid and the mixture was evaporated. The residue was crystallized from n-heptane to afford 485 mg (86%,) of 11; m.p. 116-117.5° C., [α]D +121° (c 0.4, chloroform). IR (tetrachloromethane): 3 368 (N—H, NHAc); 3 090, 3 067, 3 033, 3 007 (C—H, arom.); 1 745 (CO═OCH2COOCH3); 1 681 (amide I); 1 605, 1 587, 1 497, 1 455 (arom. ring); 1 534 (amide II); 1 439 (CH3, OCH2COOCH3). 1H NMR: 7.16-7.37 m, 15H (H-arom.); 5.65 bd, 1H, J=8.5 (NHCOCH3); 5.32 d, 1 H, J=3.5 (H-1); 4.68 d, 1 H, J=10.9 (CH2-Ph); 4.67 d, 1 H, J=12.2 (CH2-Ph); 4.66 d, 1 H, J=12.4 (CH2-Ph); 4.56 d, 1 H, J=10.9 (CH2-Ph); 4.53 d, 1 H, J=12.2 (CH2-Ph); 4.51 d, 1 H, J=12.4 (CH2-Ph); 4.48 d, 1 H, J=17.5 (OCH2CO2CH3); 4.29 d, 1 H, J=17.5 (OCH2CO2CH3); 3.96 ddd, 1 H, J=3.5, 8.5, 10.7 (H-2); 3.71 s, 3 H (OCH2CO2CH3); 3.68-3.76 m, 3 H (H-3, H-4, H-5, H-6); 3.60 dd, 1 H, J=2.0, 10.7 (H-6); 2.03 s, 3 H (NHCOCH3). 13C NMR: 172.9 (OCH2CO2CH3), 170.8 (NHCOCH3), 138.0, 137.7, 137.7, 128.5, 128.4, 128.3(3C), 128.0 (3C), 127.9(2C), 127.8(3C), 127.7 (2C) (C-arom., Bn), 96.8 (C-1), 79.6 (C-3), 79.0 (C-4), 74.9 (CH2-Ph), 73.6 (OCH2CO2CH3), 71.1 (C-5), 70.0 (CH2-Ph), 68.4 (CH2-Ph), 68.2 (C-6), 53.8 (OCH2CO2CH3), 52.0 (C-2), 23.1 (NHCOCH3). For (C32H37NO8) calculated: relative molecular mass 563.6, monoisotopic mass 563.2. FAB MS, m/z: 564.3 [M+H]+, 586.3 [M+Na]+. For C32H37NO8 (563.6) calculated: 68.19% C, 6.62% H, 2.49% N; found: 68.05% C, 6.65% H, 2.43% N.
