Chloride → HCID 14129565, compound

Participants

Reaction Steps

To a solution of benzyl 2-acetamido-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranoside [prepared by the process set forth in J. C. Jacquinet & P. Sinay, J. Org. Chem., 42, 720 (1977)] (2.34 g, 5.30 mmol), silver trifluoromethanesulfonate (1.67 g, 6.50 mmol), and 2,4,6-collidine (0.86 ml, 6.5 mmol) in dry nitromethane (27 ml) stirred at room temperature under an atmosphere of nitrogen is added a solution of 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl chloride [prepared by the process set forth in S. Akiya et al.. Chem. Pharm. Bull., 8, 583 (1960)] (2.89 g, 6.37 mmol) in dry nitromethane (15 ml). After stirring for 5 hours at room temperature, additional chloride (1.22 g, 2.69 mmol), silver trifluoromethanesulfonate (0.74 g, 2.9 mmol), and collidine (0.38 ml, 2.9 mmol) are added, and stirring is continued overnight with exclusion of moisture. The mixture is then diluted with chloroform (120 ml), undissolved solids removed by filtration, and the filter washed with chloroform (40 ml). The combined filtrates are washed with cold water, 3% aqueous hydrochloric acid, saturated aqueous sodium bicarbonate, and water. The dried (sodium sulfate) organic solution is evaporated, and the resulting syrup is treated for 3 hours at 0° with acetic anhydride (40 ml) and pyridine (60 ml). The mixture is then evaporated and coevaporated several times with toluene. The mixture is separated on dual Prep-Pak® 500 silica gel columns using a Waters Associates Prep Liquid Chromatography System 500 with 9:1 diethyl ether-dichloromethane as eluant. Benzyl 2-acetamido-4-O-(3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-β-D-glucopyranosyl)-3-O-allyl-6-O-benzyl-2-deoxy-α-D-glucopyranoside is obtained as a chromatographically homogeneous amorphous solid; yield 1.72 g (38%), [α]D25 +50° (c, 1.2, chloroform). The 300-MHz nmr spectrum in chloroform-d is in accord with the desired structure.

Provenance & Evidence