311797-26-9

Upstream product

• 4163-60-4 β-D-galactose peracetate 
• 55722-49-1 ethyl 2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranoside 
• 30628-07-0 1,2,3,4-tetra-O-acetyl-α-D-galactopyranosiduronic acid, methyl ester 
• 56768-32-2 1-bromo-2,3,4-tri-O-acetyl-α-D-galactopyranuronic acid methyl ester 
• 311797-27-0 methyl (methyl 2,3-di-O-benzyl-4-O-p-methoxybenzyl-α-D-galactopyranosyluronate)-(1->4)-(allyl 2,3-di-O-benzyl-β-D-galactopyranosid)uronate 
• 311350-26-2 methyl (ethyl 2,3-di-O-benzyl-4-O-p-methoxybenzyl-1-thio-β-D-galactopyranosid)uronate 
• 311797-21-4 ethyl 2,3-di-O-benzyl-4-O-p-methoxybenzyl-1-thio-β-D-galactopyranoside 
• 311797-20-3 ethyl 2,3-di-O-benzyl-4,6-O-p-methoxybenzylidene-1-thio-β-D-galactopyranoside 
• 311797-06-5 methyl (allyl 2-O-benzyl-3,4-O-isopropylidene-β-D-galactopyranosid)uronate 
• 311797-08-7 methyl (allyl 2-O-benzyl-β-D-galactopyranosid)uronate 
• 311797-19-0 ethyl 4,6-O-p-methoxybenzylidene-1-thio-β-D-galactopyranoside 
• 56245-60-4 ethyl 1-thio-β-D-galactopyranoside 
• 147221-64-5 methyl (allyl 3,4-O-isopropylidene-β-D-galactopyranosid)uronate 
• 95722-13-7 1,2,3,4-tetra-O-acetyl-α-D-galactopyranosiduronic acid 

Downstream Products

• 311797-25-8 methyl (methyl 2,3-di-O-benzyl-α-D-galactopyranosyluronate)-(1->4)-(allyl 2,3-di-O-benzyl-β-D-galactopyranosid)uronate 

Relevant academic research and scientific papers

Block synthesis with galacturonate trichloroacetimidates

The disaccharide methyl (4-O-benzoyl-3-O-benzyl-2-O-acetyl-α-L-rhamno pyranosyl)-(1→4)-(allyl 2,3-di-O-benzy-β-D-galactopyranosid)uronate (13) was obtained in an excellent yield of 88% using methyl (allyl 2,3-di-O-benzyl-β-D-galactopyranosid)uronate (12) as the glycosyl acceptor and a slight excess of the 1,2-di-O-acetyl-rhamnoglycosyl donor 5a. Disaccharide 13 is a key intermediate that can be used either as a glycosyl acceptor or glycosyl donor for the preparation of rhamnogalacturonan fragments. Here, introduction of the trichloroacetimidate function at the anomeric center gave the disaccharide glycosyl donor 28, which could be applied in a blockwise glycosylation reaction to form the L-Rha-α(1→4)-D-GalA-α(1→4)-D-GalA trisaccharide 29. Generally, on condition that no neighboring group effect influenced the reaction at the anomeric center of the α-trichloroacetimidate galacturonate glycosyl donors (20-22,28), α-glycosidic linkages were nearly exclusively formed, except in the case of the 4-O-methylgalactopyranosyluronate 22.

Synthesis of homogalacturonan fragments

Glycosylation of the D-galacturonic acid ester derivatives 15 and 17, which are prepared directly from D-galacturonic acid, with the thioglycosides 28 and 32, derived from the same sugar, provides α(1→4)-linked dimers. The formation of the glycosidic linkage between the galacturonic acid moieties is best achieved by iodonium di-sym-collidine perchlorate promotion. Thus, the 4'-O-p-methoxybenzyl dimer 38 can be obtained in 64% yield. Partial deprotection of the 4'-O-position provided the glycosyl acceptor 36, which was coupled with the donor 32 to yield the a(1''→4')-linked trimer 39 (48%). Approximately 8% of the β(1''→4')-coupled isomer was observed in the 13C NMR spectrum of the reaction mixture.