Ingrid 't Hart

90 Chapter 4 4 133.5 (C, Bz), 133.4 (C, Bz), 133.3 (C, Bz), 130.1, 129.8, 129.8, 129.5, 129.1, 129.0, 128.8, 128.7, 128.6, 128.3, 128.2, 125.3, 102.2 (C-1, Gal-V), 100.8 ( C H-C 6 H 5 ), 95.4 (CCl 3 , Troc), 94.3 (C-1, GalNAc-IV), 75.8 (C-4, GalNAc-IV), 73.8 (C-3, GalNAc-IV), 71.9 (C-3, Gal-V), 71.5 (C-5, Gal-V), 69.9 (C-2, Gal-V), 69.2 (C-6, GalNAc-IV), 68.2 (C-4, Gal-V), 66.4 (C-5, GalNAc-IV), 62.5 (C-6, Gal-V), 56.1 (C-2, GalNAc-IV), 34.1 (C H , TDS) 24.8 (C, TDS), 20.2 (CH 3 , TDS) 20.1 (CH 3 , TDS), 18.6 (CH 3 , TDS), 18.5 (CH 3 , TDS), -1.8 (CH 3 -Si) , -3.0 (CH 3 - Si). ESI HRMS (m/z): [M + NH] + calcd for C 58 H 62 Cl 3 NO 16 Si; 1179.3247 found 1179.3288. Dimethylthexylsilyl 2,3,4,6-tetra- O -benzoyl-β-D-galactopyranosyl-(1→3)-6- O -acetyl- 4- O -benzyl-2-[(2,2,2-trichloroethoxy)carbonylamino]-β-D-galactopyranoside (10). Compound 12 (144 mg, 0.12 mmol) was s�rred with 4 Å molecular sieves in DCM (4 mL) for 2.5 h. The mixture was cooled to -68 °C and Et 3 SiH (80 µL, 0.50 mmol) and Cl 2 PhB (50 µL, 0.38 mmol) were added. A�er 15 min Et 3 N was added and the reac�on mixture was concentrated in vacuo. The obtained residue was purified by silica column chromatography using Toluene:EtOAc (1:0 to 100:15 v/v) as the eluent to afford the desired compound . The obtained intermediate (85 mg, 0.073 mmol) was dissolved in pyridine (2 mL) and Ac 2 O (1 mL) was added. A�er 2.5 h the reac�on mixture was concentrated in vacuo and co-evaporated with Toluene. The obtained residue was purified by silica column chromatography using Toluene:EtOAc (1:0 to 10:2 v/v) as the eluent to afford compound 10 (82 mg, 55 % over 2 steps) . 1 H NMR (600 MHz, CDCl 3 ) δ 8.06 – 7.92 (6H, m, H-Ar), 7.78 (2H, d, J = 7.7 Hz, H-Ar), 7.59 – 7.14 (17H, m, H-Ar), 6.00 (1H, d, J = 3.2 Hz, H-4, Gal-V), 5.93 (1H, dd, J = 10.4, 8.0 Hz, H-2, Gal-V), 5.57 (1H, dd, J = 10.5, 3.0 Hz, H-3, Gal-V), 5.14 (1H, d, J = 11.2 Hz, CH H ), 5.04 (1H, d, J = 7.9 Hz, H-1, Gal-V), 4.94 (1H, d, J = 6.7 Hz, N H ), 4.92 (1H, d, J = 8.0 Hz, H-1, GalNAc-IV), 4.78 – 4.69 (2H, m, CH H ; H-6a, Gal-V), 4.59 (1H, dd, J = 11.0, 2.3 Hz, H-3, GalNAc-IV), 4.55 – 4.42 (3H, m, CH 2 ; H-6b, Gal-V), 4.38 – 4.32 (1H, m, H-5, Gal-V), 4.18 (1H, dd, J = 11.1, 7.3 Hz, H-6a, GalNAc-IV), 3.98 (1H, s, H-4, GalNAc-IV), 3.89 (1H, dd, J = 11.1, 5.2 Hz, H-6b, GalNAc-IV), 3.47 (1H, t, J = 6.2 Hz, H-5, GalNAc-IV), 3.33 – 3.22 (1H, m, J = 17.7, 8.3 Hz, H-2, GalNAc-IV), 1.91 (3H, s, CH 3 , OAc), 1.59 – 1.50 (1H, m, C H , TDS), 0.83 – 0.72 (12H, m, 4 x CH 3 , TDS), 0.08 (3H, s, CH 3 -Si), 0.05 (3H, s, CH 3 -Si). 13 C NMR (151 MHz, CDCl 3 ) δ 170.6 (C=O, Ac), 166.1 (C=O, Bz), 165.7 (C=O, Bz), 165.5 (C=O, Bz), 165.3 (C=O, Bz), 153.9 (C=O, Troc), 138.4 (C, Bn), 133.8 (C, Bz), 133.6 (C, Bz), 133.5 (C, Bz), 133.5 (C, Bz), 129.9, 129.9, 129.4, 129.2, 128.8, 128.8, 128.7, 128.5, 128.5, 128.4, 128.0, 102.4 (C-1, Gal-V), 95.5 (CCl 3 , Troc), 94.4 (C-1, GalNAc-IV), 77.7 (C- 3, GalNAc-IV), 75.3 (C-4, GalNAc-IV), 74.9 (CH 2 ), 74.3 (CH 2 ), 72.1 (C-5, GalNAc-IV), 71.6 (H-3, Gal-V), 71.6 (H-5, Gal-V), 70.2 (C-2, Gal-V), 68.3 (C-4, Gal-V), 63.3 (C-6, GalNAc-IV), 62.2 (C-6, Gal-V), 57.1 (C-2, GalNAc-IV), 34.1 ( C H, TDS), 24.9 (C, TDS), 20.8 (CH 3 , Ac) , 20.2 (CH 3 , TDS), 20.1 (CH 3 , TDS), 18.7 (CH 3 , TDS), 18.6 (CH 3 , TDS), -1.8 (CH 3 -Si), -3.4 (CH 3 - Si) . ESI HRMS (m/z): [M + NH] + calcd for C 60 H 66 Cl 3 NO 17 Si; 2123.3509 found 2123.3547. O BnO OAc O TrocHN O BzO OBz BzO BzO OTDS