Ingrid 't Hart

41 Chemoenzyma�c synthesis of DSGb5 2 with Et 3 N, filtered over a pad of Celite and concentrated in vacuo . The obtained residue was diluted with EtOAc, washed with NaHCO 3 . The organic layer was dried (Na 2 SO 4 ), filtered and concentrated in vacuo . The obtained crude was purified by silica column chromatography using Toluene:EtOAc (1:0 to 7:3 v/v) as the eluent to afford compound 27 (305 mg, 84 %). 1 H NMR (400 MHz, CDCl 3 ) δ 7.56 – 7.07 (40H, m, Ar-H), 5.45 (1H, s, CH-C 6 H 5 ), 5.22 – 5.09 (3H, m), 4.93 – 4.67 (6H, m), 4.54 (1H, d), 4.50 – 4.41 (3H, m, H-1, Glc-I; CH 2 , pentyl), 4.39 – 4.14 (4H, m, H-1, Gal-II), 4.01 (1H d, J = 3.5 Hz, H-4, Gal-II), 3.97 (1H, dd, J = 11.6, 7.1 Hz, H-5, Glc), 3.93 – 3.66 (5H, m, H-2, Glc-I), 3.66 – 3.58 (1H, m, H-3, Gal-II), 3.57 – 3.31 (4H, m, H-2, Gal-II; H-3, Glc-I; H-4, Glc-I), 3.28 – 3.10 (2H, m, CH 2 , pentyl), 2.92 (1H, s, H-5, Gal-II), 1.74 – 1.42 (4H, m, 2x CH 2 , pentyl), 1.41 – 1.17 (2H, m, CH 2, pentyl). 13 C NMR (101 MHz, CDCl 3 ) δ 163.5 (C=O, Cbz), 138.9, 138.8, 138.7, 138.5, 138.3, 138.1, 129.0, 128.8, 128.6, 128.6, 128.5, 128.4, 128.4, 128.3, 128.3, 128.3, 128.2, 128.2, 128.2, 128.1, 128.0, 127.8, 127.8, 127.7, 127.6, 127.5, 127.5, 127.4, 126.6, 103.6 (C-1, Glc-I), 102.9 (C-1, Gal-II), 101.4 (CH-C 6 H 5 ), 92.1, 83.0 (C-3, Gal-II), 81.8 (C-2, Gal-II), 79.6, 78.9 (C-2, Glc-I), 77.6, 7578, 75.3, 75.0, 75.0, 73.7 (C-4, Gal-II), 73.0, 71.7, 69.9, 69.0, 68.3, 67.2, 66.3 (C-5, Gal-II), 50.6, 50.3, 47.2, 46.3, 29.5, 28.0, 23.4. N-(Benzyl)-benzyloxycarbonyl-5-aminopentyl2,3,6-tri-O-benzyl-β-D-galactopyranosyl- (1 → 4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside(12b). Compound 27 (300mg,0.25mmol) was s�rred in DCM with 4 Å molecular sieves for 2 h. The mixture was cooled to -78°C and a�er adding Et 3 SiH (201 µL, 1.26 mmol) s�rring was con�nued for another 30 min. TfOH (45 µL, 0.50 mmol) was introduced. More Et 3 SiH (200 µL) and TfOH (70 µL, 0.8 mmol) were added over �me and a�er 2.5 h the reac�on mixture was quenched with Et 3 N. The quenched mixture was filtered over Celite, washed with H 2 O, sat. aq. NaHCO 3 , dried (Na 2 SO 4 ), filtered and concentrated in vacuo . The obtained residue was purified by silica gel chromatography using Toluene:EtOAc (1:0 to 5:1 v/v) as the eluent to afford compound 12b (191 mg, 64 %). 1 H NMR (400 MHz, CDCl 3 ) δ 7.59 – 6.95 (40H, m, Ar-H), 5.15 (2H, d, J = 6.7 Hz), 4.97 (1H, d, J = 10.7 Hz), 4.89 – 4.61 (6H, m), 4.61 – 4.27 (8H, m, H-1 Glc-I; H-1, Gal-II), 4.01 (1H, s, H-4, Gal-II), 3.99 – 3.91 (1H, m), 3.91 – 3.28 (13H, m, H-2, Glc-I; H-2, Gal-II), 3.28 – 3.10 (2H, m, CH 2, pentyl), 2.40 (1H, s, OH), 1.71 – 1.42 (4H, m, 2x CH 2 , pentyl), 1.42 – 1.17 (2H, m, CH 2, pentyl). 13 C NMR (101 MHz, CDCl 3 ) δ 139.1, 138.7, 138.6, 138.3, 138.2, 137.9, 128.5, 128.5, 128.4, 128.3, 128.0, 127.9, 127.8, 127.8, 127.8, 127.7, 127.6, 127.5, 127.5, 127.2, 103.6 (C-1, Glc-I), 102.5 (C-1, Gal-II), 82.9, 81.8 (C-2, Glc-I), 81.1, 79.4 (C-2, Gal-II), 76.6 (C-3, Gal-II), 75.3, 75.2, 75.1, 74.9, 73.5, 73.1, 72.7, 72.0, 68.4, 68.3, 67.1, 66.1 (C-4, Gal-II), 50.5, 50.2, 47.2, 46.2, 29.4, 28.0, 27.5, 23.4. Scheme S5. Synthesis of galactosyl donor 11 from compound 29 . 38 O O OBn BnO OBn O HO OBn BnO BnO O NBnCbz O O O NapO BnO Si SPh O O O NapO HO Si SPh O O O HO HO Si SPh i) Bu 2 SnO, toluene, reflux ii) TBAI, NapBr, 90 °C NaH, BnBr, DMF, 0°C to r.t. 11 30 29