Reaction SMILES: [CH2:1]([O:8][C@H:9]1[C@H:14]([O:15][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[C@@H:13]([CH2:23][O:24][CH2:25][C:26]2[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=2)[O:12][C@@:11]([NH2:65])([O:32][C@@H:33]2[C@@H:46]([CH2:47][O:48][CH2:49][C:50]3[CH:55]=[CH:54][CH:53]=[CH:52][CH:51]=3)[O:45][C@H:36]([O:37][CH2:38][C:39]3[CH:44]=[CH:43][CH:42]=[CH:41][CH:40]=3)[C@H:35]([NH:56][C:57](=[O:59])[CH3:58])[C@H:34]2[O:60][CH2:61][C:62]([OH:64])=[O:63])[C@@H:10]1[C:66]([O:68][CH2:69][C:70]([Cl:73])([Cl:72])[Cl:71])=[O:67])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[N+](=[CH2:76])=[N-].C(O)(=O)C>ClCCl.CO.C(OCC)C>[CH2:1]([O:8][C@H:9]1[C@H:14]([O:15][CH2:16][C:17]2[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=2)[C@@H:13]([CH2:23][O:24][CH2:25][C:26]2[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=2)[O:12][C@@:11]([NH2:65])([O:32][C@@H:33]2[C@@H:46]([CH2:47][O:48][CH2:49][C:50]3[CH:51]=[CH:52][CH:53]=[CH:54][CH:55]=3)[O:45][C@H:36]([O:37][CH2:38][C:39]3[CH:44]=[CH:43][CH:42]=[CH:41][CH:40]=3)[C@H:35]([NH:56][C:57](=[O:59])[CH3:58])[C@H:34]2[O:60][CH2:61][C:62]([O:64][CH3:76])=[O:63])[C@@H:10]1[C:66]([O:68][CH2:69][C:70]([Cl:71])([Cl:73])[Cl:72])=[O:67])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1
Reactant: CC(=O)N[C@H]1[C@@H](OCc2ccccc2)O[C@H](COCc2ccccc2)[C@@H](O[C@]2(N)O[C@H](COCc3ccccc3)[C@@H](OCc3ccccc3)[C@H](OCc3ccccc3)[C@H]2C(=O)OCC(Cl)(Cl)Cl)[C@@H]1OCC(=O)O
Reactant: C=[N+]=[N-]
Solvent: CC(=O)O
Solvent: CCOCC
Solvent: CO
Product: COC(=O)CO[C@@H]1[C@@H](NC(C)=O)[C@@H](OCc2ccccc2)O[C@H](COCc2ccccc2)[C@H]1O[C@]1(N)O[C@H](COCc2ccccc2)[C@@H](OCc2ccccc2)[C@H](OCc2ccccc2)[C@H]1C(=O)OCC(Cl)(Cl)Cl
Reaction time: 1 h
Yield: 91 %

Procedure:
To a stirred solution of 16 (1.066 mg, 1 mmol) in a mixture of dichloromethane-methanol (2:1, 75 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. Chromatography of the residue on silica gel (80 g) in chloroform-acetone (10:2) afforded 983 mg (91%) of 18 as a white solid, which was crystallized from toluene-n-heptane; m.p. 176.5-178.5° C., [α]D +49° (c 0.6, chloroform). IR (tetrachloromethane): 3 460, 3 396, 3 357 (N—H, NHAc and NHTroc); 3 090, 3 067, 3 032, 3 007 (C—H, arom.); 1 760 (C═O, OCH2COOCH3); 1 741 (CO═HNCOO and OCH2COOCH3); 1 680 (amide I); 1 607, 1 587, 1 497, 1 454 (arom. ring); 1 527, 1 521 (amide II); 1 440 (CH3, OCH2COOCH3). 1H NMR: 7.84 bd, 1 H, J=4.5 (NHCOCH3); 7.18-7.47 m, 25 H (H-arom.); 5.44 d, 1 H, J=3.4 (H-1); 4.86 d, 1 H, J=12.0 (CH2-Ph); 4.81 d, 1 H, J=12.0 (CH2CCl3); 4.77 d, 1 H, J=11.5 (CH2-Ph); 4.74 d, 1 H, J=10.9 (CH2-Ph); 4.60 d, 1 H, J=11.9 (CH2-Ph); 4.59 d, 1 H, J=11.9 (CH2-Ph); 4.57 d, 1 H, J=11.5 (CH2-Ph); 4.56 d, 1 H, J=10.9 (CH2-Ph); 4.53 d, 1 H, J=12.0 (CH2CCl3); 4.50 d, 1 H, J=11.9 (CH2-Ph); 4.49 d, 1 H, J=18.8 (OCH2CO2CH3); 4.47 d, 1 H, J=11.9 (CH2-Ph); 4.28 d, 1 H, J=18.8 (OCH2CO2CH3); 4.27 d, 1 H, J=12.0 (CH2-Ph); 4.03 d, 1 H, J=8.4 (H-1′); 3.86 bt, 1 H, J=8.9, 10.0 (H-4); 3.81 ddd, 1 H, J=3.4, 4.5, 11.0 (H-2); 3.77 dd, 1 H, J=2.6, 11.0 (H-6′a); 3.75 dd, 1 H, J=2.2, 11.0 (H-6′b); 3.71 dd, 1 H, J=8.9, 9.7 (H-4′); 3.69 dd, 1 H, J=2.3, 10.7 (H-6a); 3.64 dd, 1 H, J=8.9, 11.0 (H-3); 3.64 s, 3 H (OCH2CO2CH3); 3.57 dt, 1 H, J=2.1, 2.1, 10.0 (H-5); 3.50 dt, 1 H, J=8.4, 10.1, 10.1 (H-2′); 3.35 dd, 1 H, J=2.1, 10.7 (H-6b); 3.26 dt, 1 H, J=2.4, 2.4, 9.7 (H-5′); 3.08 bt, 1 H, J=9.6, 9.6 (H-3′); 2.00 s, 3 H (NHCOCH3); the signal of NHCO2CH2CCl3 was not observed. 13C NMR: 174.2 (OCH2CO2CH3), 170.8 (NHCOCH3), 154.0 (NHCO2CH2CCl3), 138.2, 138.1, 138.0, 137.8, 137.7, 129.8, 129.0, 128.5, 128.4 (2C), 128.4, 128.3 (2C), 128.3 (5C), 127.9 (3C), 127.8 (3C), 127.7 (2C), 127.5 (4C) (C-arom.), 100.9 (C-1′), 96.7 (C-1), 94.9 (NHCO2CH2CCl3), 82.3 (C-3′), 78.3 (C-4′), 78.0 (C-4), 77.3 (C-3), 74.9 (NHCO2CH2CCl3), 74.9 (CH2-Ph), 74.5 (CH2-Ph), 74.2 (C-5′), 73.7 (CH2-Ph), 73.3 (CH2-Ph), 70.4 (CH2-Ph), 69.6 (C-5), 69.2 (OCH2CO2CH3), 68.6 (C-6′), 67.1 (C-6), 57.5 (C-2′), 54.3 (C-2), 51.7 (OCH2CO2CH3), 23.1 (NHCOCH3). For C55H61Cl3N2O14 calculated: relative molecular mass 1 080.5, monoisotopic mass 1 078.3. FAB MS, m/z: 1 079.5, 1 081.5 [M+H]+, 1 101.5, 1 103.5 [M+Na]+. For C55H61Cl3N2O14 (1 080.5) calculated: 61.14% C, 5.69% H, 9.84% Cl, 2.59% N; found: 60.90% C, 5.85% H, 9.92% Cl, 2.62% N.