Ingrid 't Hart

82 Chapter 4 4 Figure S1. Monosaccharide labeling system for SM1-core3. 2,2,2-Trichloroace�midate 3,4,6- O -acetyl- O -2-azido-2-deoxy-α/β-D-galactopyranoside (15). Compound 15 was synthesized as described before . 28 N -(Benzyl)-benzyloxycarbonyl-5-aminopentan-1-ol (16). Compound 16 was synthesized according to previous procedures. 26 N -(Benzyl)-benzyloxycarbonyl-5-aminopentyl O -2-azido-4,6- O -benzylidene-2-deoxy- α-D-galactopyranoside (9). A mixture of acceptor 16 (1.93 g, 5.9 mmol), donor 15 (1.87 g, 3.9 mmol), thiophene (6.3 mL, 78.7 mmol) and 4 Å molecular sieves was s�rred in Et 2 O (40 mL) for 20 min. The mixture was cooled in an ice bath and TMSOTf (71 µL, 0.4mmol) was added to the mixture. The reac�on was monitored by TLC (hexanes: EtOAc 6.5 : 3.5 v/v) and more TMSOTf (2 x 140 µL) was added over �me to drive the reac�on to comple�on. A�er 2 h, Et 3 N was added, the mixture was filtered, and the filtrate concentrated in vacuo and separated between DCM and sat. aq. NaHCO 3 . The organic layer was washed with brine, dried (Na 2 SO 4 ), filtered and concentrated in vacuo . The resul�ng residue was purified by silica column chromatography using Hexane:EtOAc (1:0 to 24 : 8 v/v) as the eluent affording the product as an α/β mixture (1.57 g, 62 %). The obtained α/β mixture of compound 20 was dissolved in MeOH (25 mL) and freshly prepared NaOMe (2.5 mL) was added. A�er 1 h H + Amberilte resin was added, the mixture was filtered and concentrated in vacuo . Compound 21 was used in the next reac�on without further purifica�on. Benzaldehyde dimethyl acetal (444 µL, 2.96 mmol) and pTsOH·H 2 O (43 mg, 0.23 mmol) were added to a solu�on of compound 21 (1.17 g, 2.27mmol) in CH 3 CN (25mL). A�er 1 h themixturewas quenchedwith Et 3 N, concentrated in vacuo and the obtained residue was purified by silica column chromatography using toluene:EtOAc (1:0 to 8:2 v/v) as the eluent to obtain compound 9 (α-anomer: 688 mg, 50 %; β-anomer: 490 mg, 36 %). The NMRs of the α-anomer are depicted below. 1 H NMR (600 MHz, CDCl 3 ) δ 7.52 – 7.46 (2H, m, H-Ar), 7.42 – 7.10 (13H, m, H-Ar), 5.57 (1H, s, C H -C 6 H 5 ), 5.18 (2H, d, J = 20.1 Hz, CH 2 ), 4.96 (1H, d, J = 13.9 Hz, H-1), 4.50 (2H, d, J = 12.0 Hz, CH 2 ), 4.31 – 4.22 (2H, m, H-4; H-6a), 4.21 – 4.11 (1H, m, H-3), 4.11 – 4.02 (1H, m, H-6b), 3.78 – 3.58 (2H, m, H-5; C H H, pentyl), 3.53 (1H, d, J = 8.8 Hz, H-2), 3.49 – 3.34 (1H, m, CH H , pentyl), 3.34 – 3.13 (2H, m, CH 2 , pentyl), 2.42 (1H, d, J = 10.8 Hz, O H ), 1.68 – 1.46 (4H, m, 2x CH 2 , pentyl), 1.41 – 1.24 (2H, m, 2x CH 2 , pentyl). 13 C NMR (151 MHz, CDCl 3 ) δ 137.3 (C=O, Cbz), 129.4, 128.6, 128.5, 128. 3, 127.9, 127.8, 127.2, 126.2, 101.3 ( C H-C 6 H 5 ), 98.7 (C-1), 75.5 (C-4), 69.3 (C-6), 68.4 (CH 2 , pentyl), 67.4 (C-3), 67.2 (CH 2 ), 62.8 (C-5), 60.7 (C-2), 50.3 (CH 2 ), 47.1 (CH 2 , pentyl), 29.1 (CH 2 , pentyl), 27.4 (CH 2 , pentyl), 23.4 O NHAc O HO OH O AcHN O O OH OH NH 2 O OH O NaO 3 SO OH O HO OH O AcHN O HO OH HO HO I II III IV V O AcO OAc AcO N 3 O CCl 3 NH HO NBnCbz O O O HO N 3 O Ph NBnCbz