Boron trifluoride etherate → HCID 131728729, compound

Participants

Reaction Conditions

Reaction Steps

D-Fucose (3) (4.95 g, 30.14 mmol) was dissolved in 30 mL of acetic anhydride and 30 mL of pyridine and stirred for 12 h. The solvent was removed in vacuo. Column chromatography (2:1 hexane/EtOAc) yielded 10.15 g (quant.) of 1,2,3,4-tetraacetyl-D-fucose (as a mixture of α-and β-anomer). 1,2,3,4-tetraacetyl-D-fucose (20.0 g, 60.2 mmol) and p-methoxyphenol (MPOH) (10.46 g, 84.3 mmol) were dissolved in 220 mL of dichloromethane and cooled to 0° C. BF3.OEt2 (21.4 g, 19.0 mL, 150.5 mmol) was added and the mixture stirred overnight. The reaction mixture was quenched by addition of saturated NaHCO3 solution, washed 2 times with water, dried over Na2SO4, concentrated and the residue was purified by column chromatography (3:1 hexane/EtOAc) yielding 16.8 g (71%) of 4-methoxyphenyl 1,2,3,4tetraacetyl-α-D-fucose (Only the β-anomer reacts, α-anomer could be recovered). 4-methoxyphenyl 1,2,3,4-tetraacetyl-α-D-fucose (3.90 g, 9.85 mmol) was dissolved in 150 mL of methanol and 6 mL of 0.5 M NaOMe solution were added. The mixture was stirred for 6 h. The solvent was removed in vacuo. Column chromatography (3:1 dichloromethane/methanol) afforded 2.63 g (99%) as a colorless solid: [α]D: +201.6 (c=0.32, CH3OH). 1H NMR (CD3OD, 300 MHz) δ 1.18 (d, J=6.6 Hz, 3H), 3.74 (s, 3H), 3.89 (m, 2H), 4.09 (quart., J=6.0 Hz, 1H), 5.31 (d, J=3.6 Hz, 1H), 6.82 (d, J=9.3 Hz, 2H), 7.04 (d, J=9.3 Hz, 2H). 13C NMR (CD3OD, 75 MHz) 16.3, 55.7, 67.9, 69.5, 71.2, 73.2, 100.0, 115.1, 119.0, 152.2, 156.0. MALDI-HRMS: m/z [M+Na]+ calcd 293.0996, obsd 293.0994.

Provenance & Evidence