Dichloromethane → 2,3,4,6-Tetra-O-benzoyl-beta-D-galactopyranosyl-(1->4)-1,2,3,6-tetra-O-benzoyl-D-glucopyranose

Participants

Reaction Steps

Lactose (1.0 g, 2.92 mmol) was dissolved in dry pyridine (20 mL) at 0° C. DMAP (cat.) was added. Benzoyl chloride (2.5 equiv., 58 mmol, 6.8 mL) was added dropwise and the solution stirred at room temperature overnight. The solution was poured onto a mixture of ice-water and DCM. The organic layer was washed with NaHCO3(sat.) (×7), brine, H2SO4 (5%) (×2), followed by brine. The solution was dried (Na2SO4) and the solvent evaporated. The product was passed through a short silica plug to remove the remaining benzoyl chloride and the solvent was evaporated to yield 3.67 g (quantitative) of the white solid product which was reacted on without further purification or characterisation.

Provenance & Evidence