202864-99-1

Upstream product

• 202864-98-0 p-methoxyphenyl O-[3,6-di-O-benzyl-2-deoxy-2-(4,5-dichlorophthalimido)-4-O-levulinoyl-β-D-glucopyranosyl]-(1->4)-3,6-di-O-benzyl-2-deoxy-2-(4,5-dichlorophthalimido)-β-D-glucopyranoside 
• 942-06-3 4,5-dichlorophthalic anhydride 
• 5432-46-2 1,3,4,6-tetra-O-acetyl-D-glucosamine hydrochloride 
• 202864-93-5 p-methoxyphenyl 4,6-O-benzylidene-2-deoxy-2-(4,5-dichlorophthalimido)-β-D-glucopyranoside 
• 202864-92-4 Acetic acid (2R,3S,4R,5R,6S)-3-acetoxy-2-acetoxymethyl-5-(5,6-dichloro-1,3-dioxo-1,3-dihydro-isoindol-2-yl)-6-(4-methoxy-phenoxy)-tetrahydro-pyran-4-yl ester 
• 202865-12-1 4-Oxo-pentanoic acid (2R,3S,4R,5R,6R)-4-benzyloxy-2-benzyloxymethyl-5-(5,6-dichloro-1,3-dioxo-1,3-dihydro-isoindol-2-yl)-6-hydroxy-tetrahydro-pyran-3-yl ester 
• 202864-95-7 p-methoxyphenyl 3,6-di-O-benzyl-2-deoxy-2-(4,5-dichlorophthalimido)-β-D-glucopyranoside 
• 202864-94-6 2-[(2R,4aR,6S,7R,8R,8aS)-8-Benzyloxy-6-(4-methoxy-phenoxy)-2-phenyl-hexahydro-pyrano[3,2-d][1,3]dioxin-7-yl]-5,6-dichloro-isoindole-1,3-dione 
• 202864-97-9 4-Oxo-pentanoic acid (2R,3S,4R,5R,6S)-4-benzyloxy-2-benzyloxymethyl-5-(5,6-dichloro-1,3-dioxo-1,3-dihydro-isoindol-2-yl)-6-(2,2,2-trichloro-acetimidoyloxy)-tetrahydro-pyran-3-yl ester 
• 202864-96-8 4-Oxo-pentanoic acid (2R,3S,4R,5R,6S)-4-benzyloxy-2-benzyloxymethyl-5-(5,6-dichloro-1,3-dioxo-1,3-dihydro-isoindol-2-yl)-6-(4-methoxy-phenoxy)-tetrahydro-pyran-3-yl ester 
• 202865-03-0 p-methoxyphenyl 3,6-di-O-benzyl-4-O-chloroacetyl-2-deoxy-2-(4,5-dichlorophthalimido)-β-D-glucopyranoside 
• 202865-02-9 p-methoxyphenyl 4-O-acetyl-3,6-di-O-benzyl-2-deoxy-2-(4,5-dichlorophthalimido)-β-D-glucopyranoside 

Relevant academic research and scientific papers

On the stereochemistry of tethered intermediates in p-methoxybenzyl- assisted β-mannosylation

We have previously developed a novel method for the stereocontrolled synthesis of β-manno-glycoside. Starting from 2-O-PMB (p-methoxybenzyl)- protected mannosyl donor 1, conversion into the mixed acetal 3 under oxidative conditions followed by the activation of the anomeric position affords β-manno-glycoside as a single stereoisomer. Although the utility of this method has been further demonstrated in the synthesis of the core structure of Asn-linked glycan chains, there remained uncertainty with respect to the stereochemistry of the mixed acetal. In order to make a stereochemical assignment of this intermediate, diastereomeric acetals 14a, 15a and 14b, 15b were prepared from 9 + 10/7 and 11 + 12/13, respectively. Investigations by means of NMR and a computational approach using DADAS 90 for quantifying steric hindrance, resulted in the conclusion that 14a/15a derived from 2-O-PMB-protected 9 has an (S) configuration and 14b/15b derived from 2-O-unprotected 11 has an (R) configuration. Based on the characteristic 1H-NMR patterns inherent to the (S) isomers 4,6-O-benzylidene-protected 30- 35, derived from thiomannosides 5, 23, 24, 26, 27, were also revealed to have the (S) configuration.

Use of dichlorophthaloyl (DCPhth) group as an amino protecting group in oligosaccharide synthesis

As an alternative to phthaloyl (Phth) group, 4,5-dichlorophthaloyl (DCPhth) group was investigated as an amino protecting group to prove it to be useful for the synthesis of β-glycosides of 2-acetamido-2-deoxy glucose (GlcNAc). DCPhth was introduced onto the C-2 nitrogen of glucosamine to give 2, which was further transformed into mono- and di- and trisaccharide derivatives which constitute basic structural units of asparagine linked glycoprotein oligosaccharides. DCPhth group proved to have sufficient stability under the standard conditions of protecting group manipulations (e.g. deacetylation, benzylation, benzylidenation), and Lewis acid-, silver salt- and iodonium ion-promoted glycosylation. Removal of DCPhth group was smoothly performed by using ethylenediamine in alcoholic solvent under substantially milder conditions required for deprotection of Phth.