Ingrid 't Hart

83 Chemical synthesis of sulfoglycolipid analog SM1a-core3 4 (CH 2 , pentyl). ESI HRMS ( m/z ): [M + Na] + calcd for C 33 H 38 N 4 O 7 ; 625.2638 found 625.2615. Dimethylthexylsilyl 4- O -acetyl-3,6-di- O -benzyl-2-deoxy-2-phthalimido-β-D-gluco- pyranoside (23). Compound 22 was synthesized according to a reported procedure. 29 Compound 22 (3.48 g, 5.5 mmol) was dissolved in pyridine (10 mL) and Ac 2 O (1.04 mL) was added to the s�rring mixture. The reac�on mixture was s�rred for 1 h and concentrated in vacuo . The obtained oil was dissolved in EtOAc, washed with sat. aq. NaHCO 3 and brine, dried (Na 2 SO 4 ), filtered, concentrated in vacuo. The obtained residue was purified by silica column chromatography using Hexane:EtOAc (1:0 to 43 : 7) as the eluent to afford compound 23 (3.00 g, 81 %). 1 H NMR (400 MHz, CDCl 3 ) δ 7.88 – 7.66 (4H, m, H-Ar), 7.39 – 7.24 (5H, m, H-Ar), 7.04 – 6.89 (5H, m, H-Ar), 5.37 (1H, d, J = 8.0 Hz, H-1), 5.12 (1H, t, J = 9.5 Hz, H-4), 4.59 (1H, d, J = 12.0 Hz, CH H , Bn), 4.55 (s, 2H, CH 2 ), 4.45 (1H dd, H-3), 4.35 (1H, d, J = 12.0 Hz, CH H , Bn), 4.21 (1H, dd, J = 10.9, 8.1 Hz, H-2), 3.81 – 3.71 (1H, m, H-5), 3.65 – 3.56 (2H, m, H-6), 1.95 (3H, s, OAc), 1.42 – 1.30 (1H, m, C H , TDS), 0.66 – 0.54 (12H, m, 4x CH 3 , TDS), 0.12 (3H, s, CH 3 -Si), -0.03 (3H, s, CH 3 -Si). 13 C NMR (101 MHz, CDCl 3 ) δ 169.7 (C, OAc), 138.1 (C, Phth), 137.8 (C, Phth), 133.8, 128.3, 128.1, 127.8, 127.7, 127.6, 127.4, 123.1 (CH, Phth), 93.3 (C-1), 76.7 (C-3), 73.5 (CH 2, Bn), 73.5 (CH 2 , Bn), 73.5 (C-5), 72.6 (C-4), 70.0 (C-6), 57.5 (C-2), 33.8 ( C H, TDS), 24.5 (C, TDS), 20.9 (CH 3 , OAc) , 19.8 (CH 3 , TDS), 19.7 (CH 3 , TDS), 18.3 (CH 3 , TDS), 18.2 (CH 3 , TDS) ,-1.8 (CH 3 -Si) , -3.9 (CH 3 -Si). ESI HRMS ( m/z ): [M + Na] + calcd for C 38 H 47 NO 8 Si; 696.2969 found 696.2930 2,2,2-Trichloroace�midate 4- O -acetyl-3,6-di- O -benzyl-2-deoxy-2-phthalimido-β-D- glucopyranoside (8). HF·pyridine (70% HF, 3.0 mL) was added to a s�rring solu�on of compound 23 (3.0 g, 4.5 mmol) in pyridine (25 mL) in a plas�c round bo�omflask. A�er overnight s�rring, sat. aq. NaHCO 3 was added to the mixture and s�rring was con�ntued for another 30 min. The reac�on mixture was diluted with EtOAc, washed with sat. aq. NaHCO 3 , brine and dried (Na 2 SO 4 ), filtered, and the filtrate concentrated in vacuo to give a residue that was co-evaporated with toluene (3x) and DCM (1x). Crystalliza�on fromDCM/Hexane afforded compound 24 (2.14 g, 90 %). 2,2,2-Trichloroacetonitrile (471 µL, 4.7 mmol) and DBU (28 µL, 0.19 mmol) were added to a s�rring solu�on of compound 24 (500 mg, 0.94 mmol) in DCM (10 mL) at 0 °C. A�er 1 h the reac�on mixture was concentrated in vacuo and the obtained residue was directly purified by silica column chromatography using Hexane(1% Et 3 N):EtOAc (1:0 to 3:1 v/v) as the eluent to afford compound 8 (572 mg, 90 %). 1 H NMR (600 MHz, CDCl 3 ) δ 8.58 (1H, s, N H ), 7.76 – 7.62 (4H, m, H-Ar), 7.38 – 7.30 (5H, m, H-Ar), 7.06 – 6.85 (5H, m, H-Ar), 6.43 (1H, d, J = 8.5 Hz, H-1), 5.25 (1H, dd, J = 10.0, 8.6 Hz, H-4), 4.63 (1H, d, J = 12.1 Hz, CH H , Bn), 4.60 – 4.50 (4H, m, H-3; CH 2, Bn; H-2), 4.36 (1H, d, J = 12.1 Hz, CH H , Bn), 3.95 (1H, ddd, J = 10.0, 5.0, 3.6 Hz, H-5), 3.70 – 3.61 (2H, m, H-6), 1.94 (3H, s, OAc). 13 C NMR (151 MHz, CDCl 3 ) δ 169.5 (C, OAc), 160.8 (C=NH), 137.8 (C, Phth), 137.6 (C, Phth), 134.0, 131.4, 128.4, 128.1, 128.0, 127.8, 127.7, 127.5, 123.4, 93.9 (C-1), 90.3 (CCl 3 ), 76.7 (C-3), 74.5 (C-5), 74.0 (CH 2, Bn), 73.5 (CH 2 , Bn), 71.9 (C-4), 69.0 (C-6), 54.4 (C-2), 20.9 (CH 3, OAc). Open anomer: ESI HRMS ( m/z ): [M + Na] + calcd for C 30 H 29 NO 8 ; 554.1791 found 554.1818. O NPht BnO AcO BnO OTDS O NPht BnO AcO BnO O CCl 3 NH