N-Acetyl-1,6-bis-O-(phenylMethyl)-4-O-[3,4,6-tri-O-acetyl-2-deoxy-2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)-β-D-gl synthesis

Yield:112289-92-6 33%

Reaction Conditions:

with silver trifluoromethanesulfonate in dichloromethane at 20;Molecular sieve;Inert atmosphere;

Steps:

A.7 Synthesis of Benzyl 2-acetamido-4-0-(3,4,6-tri-0-acetyl-2-deoxy-2-phthalimido-fi-d- glucopyranosyl)-6-0-benzyl-2-deoxy 3-0-[(R)- 1 -(methoxycarbonyl)ethyl]-ct-d-gluco- pyranoside (4)

The glucosyl chloride 3 (280 mg; 0.62 mmol) and protected muramic acid 2 (100 mg; 0.21 mmol) with silver triflate (AgTf; 210 mg; 0.82 mmol) as catalyst were subjected to the Anderson's apparatus for glycosidic coupling (Nashed and Anderson, 1982), molecular sieves and dry DCM (2 mL) were added and reaction was stirred under nitrogen at room temperature overnight. Thereafter, chloroform was added to the formed suspension and centrifuged. The residue was washed two times with chloroform. Collected chloroform's supernatants were washed with saturated aqueous solution of NaHCO₃, water, and dried over Na₂SO₄. Solvent was evaporated and product purified by flash silica gel column chromatography in solvent systems diethyl ethenpetroleum ether:iPrOH 8:4:1 and DCM:MeOH 9:1. After the second column compound 4 (62 mg; 33%) was obtained. ESI-MS: C46H53N2O17 905.4 [M+H]⁺ calc. 905.3; C46H52N2NaO17 927.4 [M+Na]⁺ calc. 927.3; Rf = 0.54 (diethyl ethenpetroleum ether:isopropanol 8:4:1 ).

References:

WO2016/173603,2016,A1 Location in patent:Page/Page column 16