Ingrid 't Hart

91 Chemical synthesis of sulfoglycolipid analog SM1a-core3 4 ( N -phenyl)-2,2,2-trifluoroace�midate 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 (3). HF·Pyridine (70% HF, 80 µL) was added to a s�rring solu�on of compound 10 (80 mg, 0.066 mmol) in pyridine (1 mL) in a plas�c round bo�om flask. A�er overnight s�rring the mixture was diluted with DCM and quenched by addi�on of sat. aq. NaHCO 3 . The organic phase was washed with sat. aq. NaHCO 3 , the aq. layers were extracted with DCM and the combined organic phases were dried (Na 2 SO 4 ), filtered, concentrated in vacuo and co-evaporated with toluene. The obtained residue was dissolved in DCM (1 mL) and Cs 2 CO 3 (86 mg, 0.27 mmol) and CF 3 NPhimidate (159 L, 0.99 mmol) were added. A�er 3 h the mixture was concentrated in vacuo . 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 3 (51 mg, 62 % over 2 steps) . 1 H NMR (600 MHz, CDCl 3 ) δ 8.01 – 7.93 (6H, m, H-Ar), 7.76 (2H, d, J = 7.8 Hz, H-Ar), 7.58 – 7.14 (19H, m, H-Ar), 7.09 (1H, t, J = 7.5 Hz, H-Ar), 6.74 (2H, d, J = 7.4 Hz, H-Ar), 6.04 (1H, d, J = 2.9 Hz, H-4, Gal-V), 5.99 – 5.90 (1H, m, H-2, Gal-V), 5.68 (1H, d, J = 9.9 Hz, H-3, Gal-V), 5.26 – 5.13 (2H, m, CH H ; H-1, Gal-V), 4.93 (1H, s, N H ), 4.80 – 4.74 (1H, m, H-6a, Gal-V), 4.70 (1H, d, J = 10.8 Hz, CH H ), 4.54 – 4.43 (4H, m, H-2, GalNAc-IV; H-6b, Gal-V; CH H ; H-5, Gal-V), 4.21 – 4.13 (2H, m, H-3, GalNAc-IV; H-6a, GalNAc-IV), 4.09 – 4.04 (1H, m, H-4, GalNAc-IV), 4.01 (1H, dd, J = 11.1, 4.7 Hz, H-6b, GalNAc-IV), 3.93 (1H, s, H-5, GalNAc-IV), 3.40 (1H, d, J = 12.1 Hz, CH H ), 1.97 (3H, s, CH 3 , OAc). 13 C NMR (151 MHz, CDCl 3 ) δ 170.4 (C=O, Ac), 165.9 (C=O, Bz), 165.7 (C=O, Bz), 165.6 (C=O, Bz), 165.4 (C=O, Bz), 153.7 (C=O, Troc), 143.1 (C, NPh), 137.9 (C, Bn), 133.8 (C, Bz), 133.5 (C, Bz), 133.5 (C, Bz), 133.4 (C, Bz), 129.8, 129.8, 129.6, 129.1, 128.9, 128.7, 128.6, 128.5, 128.4, 128.0, 125.3, 119.2, 102.4 (C-1, Gal-V), 95.4 (CCl 3 , Troc), 77.5 (C-4, GalNAc-IV), 75.2 (C-3, GalNAc-IV), 75.1 (CH 2 ), 73.9 (CH 2 ), 71.9 (C-5, Gal-V), 71.4 (C-3, Gal-V), 70.9 (C-5, GalNAc-IV), 69.9 (C-2, Gal-V), 68.1 (C- 4, Gal-V), 63.0 (C-6, GalNAc-IV), 62.1 (C-6, Gal-V), 50.1 (C-2, GalNAc-IV), 20.7 (CH 3 , Ac). Scheme S4. Chemical glycosyla�on of disaccharide donor 3 with trisaccharide acceptor 4 provided pentasaccharide 2 . Reagents and condi�ons: (a) TMSOTf, CH 2 Cl 2 , 4 Å MS, -74 °C. 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 O NPhth O BnO BnO O N 3 O O O O NBnCbz Ph O OBn HO NapO OBz O BnO OAc O TrocHN O BzO OBz BzO BzO O CF 3 NPh a + 3 4 2 , 40% O BnO OAc O TrocHN O BzO OBz BzO BzO O CF 3 NPh