反应详情

Part C: Ethyl 3-(2-hydroxyphenyl)benzyloxyacetate (0.85 g, 2.97 mmol) was dissolved in 1,2-dichloroethane (25 ml) in a dry 50 ml flask. L-Fucose tetraacetate (1.97 g, 5.94 mmol) was added in one portion, then boron trifluoride etherate (1.86 ml, 14.84 mmol) was added slowly. The mixture was stirred under nitrogen overnight at room temperature then mixed with water (50 ml). The organic material was separated and the aqueous portion was extracted with dichloromethane (3×5 ml). The extracts were combined with the original organic fraction, dried (MgSO4) then concentrated under reduced pressure. The residue was purified by flash chromatography (SiO2, gradient elution hexane to 3:1 hexane/ethyl acetate) which provided 1.0 g (61%) of ethyl 3-(2-(2,3,4-tri-O acetyl-α-L-fucopyranosyloxy)phenyl)benzyloxyacetate.

1. customThe organic material was separated
2. extractionthe aqueous portion was extracted with dichloromethane (3×5 ml)
3. dry with materialdried (MgSO4)
4. concentrationthen concentrated under reduced pressure
5. customThe residue was purified by flash chromatography (SiO2, gradient elution hexane to 3:1 hexane/ethyl acetate) which