215722-00-2

Upstream product

• 129575-89-9 p-methoxyphenyl 3,6-di-O-benzyl-2-deoxy-2-phthalimido-β-D-glucopyranoside 
• 215721-98-5 methyl 4,6-O-cyclohexylidene-2-O-p-methoxybenzyl-3-O-tert-butyldiphenylsilyl-1-thio-α-D-mannopyranoside 
• 80734-76-5 methyl 1-thio-α-D-mannopyranoside 
• 64550-71-6 methyl 2,3,4,6-tetra-O-acetyl-1-thio-α-D-mannopyranoside 
• 215721-96-3 methyl 4,6-O-cyclohexylidene-2,3-O-p-methoxybenzylidene-1-thio-α-D-manopyranoside 
• 215721-97-4 methyl 4,6-O-cyclohexylidene-2-O-p-methoxybenzyl-1-thio-α-D-mannopyranoside 
• 215721-95-2 methyl 4,6-O-cyclohexylidene-1-thio-α-D-mannopyranoside 
• 933-40-4 cycloxexanone dimethyl ketal 

Relevant academic research and scientific papers

On the mechanism of p-methoxybenzylidene assisted intramolecular aglycon delivery

p-Methoxybenzylidene-assisted intramolecular aglycon delivery was developed in this laboratory and has been demonstrated to be highly efficient and versatile particularly for the synthesis of complex glycoprotein-related glycans. It was revealed that the reaction course of IAD can be clearly monitored by performing the reaction in an NMR tube. Our results suggest that the nonhydrolytic pathway that converts metastable intermediate 3 to the product is functional. Comparative experiments in the presence and absence of water in the reaction media afforded supporting evidence eliminating the possibility of fortuitous contamination of water under standard IAD conditions.

Highly optimized β-mannosylation via p-methoxybenzyl assisted intramolecular aglycon delivery

Highly efficient and stereoselective β-mannosylation was achieved by using mannosyl thioglycosides 5 and 19. Intramolecular aglycon delivery (IAD) from mixed acetal 12, 15 and 20, obtainable by oxidative coupling of aglycon onto mannosyl thio-glycosides which carry p-methoxybenzyl (PMB) group at C-2 position, was performed by the action of MeOSO2CF3 to afford β-mannosides 13/16/21. It is to be noted that efficiency of IAD was substantially improved by changing the protecting group at the 4- and 6- positions from previously utilized benzylidene to cyclohexylidene (5) or TIPDS (19) group. As a result, it is now possible to perform the β-manno glycosylation in a highly optimized manner to afford di- and trisaccharides with a backbone structure corresponding to asparagine-linked oligosaccharides in 75-85% yield as single stereoisomers.