Ingrid 't Hart

92 Chapter 4 4 5-aminopentyl 2,3,4,6-tetra- O -benzoyl-β-D-galactopyranosyl-(1→3)-4- O -acetyl-6- O - benzyl-2-[(2,2,2-trichloroethoxy)carbonylamino]-β-D-galactopyranosyl-(1→4)-2- O - benzoyl-6- O -benzyl-3- O -(2-naphthyl)methyl-β-D-glucopyranosyl-3,6-di- O -benzyl-2- deoxy-2-phthalimido-β-D-glucopyranosyl-(1→3)-2-azido-4,6- O -benzylidene-2-deoxy- α-D-galactopyranoside (2). A mixture of acceptor 4 (54 mg, 0.034 mmol), donor 3 (51 mg, 0.041 mmol) and 4 Å molecular sieves was s�rred in DCM (2 mL) for 2 h. The mixture was cooled to -74 °C and TMSOTf (1.24 µL, 0.0069 mmol) in DCM (200 µL) was added. The reac�on was monitored by MALDI-TOF-MS and a�er 30 min Et 3 N was added. The mixture was allowed to warm to room temperature, filtered over a pad of Celite and concentrated in vacuo . The obtained residue was purified by SX1 size exclusion chromatography using Toluene:Acetone (1:1 v/v) as the eluent to afford compound 2 (34 mg, 40 %). 1 H NMR (600 MHz, CDCl 3 ) δ 8.04 – 7.91 (8H, m, H-Ar), 7.81 – 7.09 (56H, m, H-Ar), 7.05 (2H, d, J = 5.9 Hz, H-Ar), 6.89 (2H, d, J = 7.5 Hz, H-Ar), 6.80 (2H, t, J = 7.5 Hz, H-Ar), 6.68 (1H, t, J = 7.3 Hz, H-Ar), 5.98 (1H, d, J = 3.0 Hz, H-4, Gal-V), 5.92 (1H, dd, J = 10.2, 8.3 Hz, H-2, Gal-V), 5.42 (1H, dd, J = 10.5, 3.1 Hz, H-3, Gal-V), 5.40 – 5.36 (1H, m, H-2, Gal-III), 5.31 – 5.22 (3H, m, C H -C 6 H 5 ; H-1, GlcNAc-II; N H Troc), 5.15 (3H, d, J = 10.7 Hz, CH 2 ; C H H), 5.08 (1H, d, J = 8.2 Hz, H-1, GalNAc-IV), 4.95 (1H, d, J = 8.0 Hz, H-1, Gal-V), 4.81 – 4.59 (8H, m, CH H ; H-6a, Gal-V; H-1, GalNAc-I; CH H ; CH H ; CH H ; H-3, GalNAc-IV; H-1, Gal-III), 4.54 – 4.38 (4H, m, J = 21.3, 17.9, 9.4 Hz, CH H ; CH 2 ; H-6b, Gal-V), 4.37 – 4.16 (9H, m, CH H ; H-3, GlcNAc-II; H-4, GalNAc-I; CH H ; CH 2 ; H-2, GlcNAc-II; H-5, Gal-V; H-4, Gal-III), 4.14 – 4.06 (2H, H-6, GalNAc-IV), 4.06 – 3.91 (4H, m, CH H ; CH H ; H-6a, GalNAc-I; H-4, GalNAc-IV), 3.89 – 3.76 (2H, m, H-4, GlcNAc-II; H-3, GalNAc-I), 3.60 – 3.09 (16H, m, H-3, Gal-III; H-6b, GalNAc-I; H-5, Gal-III; H-6a, Gal-III; H-5, GalNAc-IV; CH H , pentyl; H-6, GlcNAc-II; H-5, GlcNAc-II; H-5, GalNAc-I; H-2, GalNAc-IV; H-6b, Gal-III; CH H , pentyl; CH 2 , pentyl), 1.87 (3H, s, CH 3 , OAc), 1.46 (4H, d, J = 34.4 Hz, 2x CH 2 , pentyl), 1.24 – 1.10 (2H, m, CH 2 , pentyl). 13 C NMR (151 MHz, CDCl 3 ) δ 170.5 (C=O, Ac), 166.0 (C=O, Bz), 165.5 (C=O, Bz), 165.4 (C=O, Bz), 165.4 (C=O, Bz), 164.6 (C=O, Cbz), 154.3 (C=O, Troc), 138.4 , 138.3, 138.3, 138.0, 137.9, 137.9, 137.7, 134.8, 133.6, 133.6, 133.4, 133.3, 133.3, 133.1, 131.8, 129.9, 129.8, 129.8, 129.4, 129.3, 129.1, 129.1, 129.0, 128.7, 128.7, 128.6, 128.5, 128.4, 128.3, 128.3, 128.0, 127.9, 127.9, 127.7, 127.7, 127.5, 127.4, 127.3, 127.2, 126.9, 126.3, 126.2, 126.0, 125.9, 125. 3, 123.2, 102.0 (C-1, Gal-V), 101.0 (C-1, Gal-III), 100.3 ( C H-C 6 H 5 ), 99.7 (C-1, GlcNAc-II), 99.2 (C-1, GalNAc-IV), 98.4 (C-1, GalNAc-I), 96.0 (CCl 3 , Troc), 79.7 (C-3, Gal-III), 78.2 (C-3, GalNAc-I), 77.5 (C-3, GlcNAc-II), 76.9 (C-3, GalNAc-IV), 75.9 (C-4, GlcNAc-II), 75.3 (C-4, GalNAc-I), 75.2 (C-4, GalNAc-IV), 75.0 (CH 2 ), 74.6 (CH 2 ), 74.4 (C-5, GalNAc-IV), 74.0 (CH 2 ), 73.9 (C-5, GlcNAc-II), 73.5 (CH 2 ), 73.4 (CH 2 ), 71.9 (C-5, Gal-III), 71.9 (C-2, Gal-III), 71.8 (CH 2 ), 71.5 (C-3, Gal-V), 71.3 (C-5, Gal-V), 71.1 (C-4, Gal- III), 69.7 (C-2, Gal-V), 69.1 (C-6, GlcNAc-II), 68.9 (C-6, GalNAc-I), 68.8 (C-6, Gal-III), 68.2 (C- 4, Gal-V), 68.1 (CH 2 , pentyl), 67.2 (CH 2 ), 62.9 (C-5, GalNAc-I), 62.8 (C-6, GalNAc-IV), 61.8 (C-6, Gal-V), 58.1 (C-2, GalNAc-I), 55.6 (C-2, GlcNAc-II), 55.2 (C-2, GalNAc-IV), 50.5 (CH 2 ) 46.1 (CH 2 , pentyl), 29.0 (CH 2 , pentyl), 27.4 (CH 2 , pentyl) , 23.2 (CH 2 , pentyl), 20.8 (CH 3 , OAc). ESI HRMS (m/z): [M + NH 4 ] + calcd for C 144 H 137 Cl 3 N 6 O 35 ; 2632.8529 found 2632.8522. O NPhth O BnO BnO O N 3 O O O O NBnCbz Ph O OBn O NapO OBz O BnO OAc O TrocHN O BzO OBz BzO BzO