2-Bromoethyl 2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl)-beta-D-galactopyranoside → 2-(p-Aminophenylthio)ethyl 4-O-(alpha-D-galactopyranosyl)-beta-D-galactopyranoside

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Reaction Steps

2-Bromoethyl 2,3,6-tri-O-acetyl-4-O-(2,3,4,6-tetra-O-acetyl-αD-galactopyranosyl)-β-D-galactopyranoside (15) (170 mg; 0.23 mmol) was treated as above (compound 26). The crude product, that was obtained after the deacetylation reaction, was filtered through a column (SiO2, ethyl acetate/methanol 2:3) which gave the title compound (27) as an amorphous solid. Yield: 110 mg (97%). Chromatography (SiO2, chloroform/methanol/water 65:35:10; lower phase) gave an analytical sample: [α]D23 +70.6° (c 0.58; H2O); 1H-NMR (DMSO-D6 plus D2O, 50°) δ 7.13, 6.56 (d, 2H each, J=8.4 Hz, aromatic H), 4.83 (d, 1H, J=3.3 Hz, H1'), 4.14 (d, 1H, J=7.6 Hz, H1), 2.89 (t, 2H, J=7.5 Hz, CH2 --S) ppm. 13C-NMR (DMSO-D6 plus D2O) δ 149.1, 136.5, 124.8, 119.7 (aromatic C), 105.7, (Cl), 102.9 (Cl'), 79.8, 77.7, 75.1, 73.6, 73.5, 71.9, 71.7, 71.4, 70.8 (C2-C5, C2'-C5', CH2O), 63.3, 62.8 (C6, C6'), 37.6 (CH2Br) ppm.

Provenance & Evidence