400091-19-2

Upstream product

• 1125-88-8 benzaldehyde dimethyl acetal 
• 13992-16-0 1-deoxy-1-(phenylthio)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose 
• 16758-34-2 1-thiophenyl-β-D-galactopyranoside 
• 3282-30-2 pivaloyl chloride 
• 400091-18-1 phenyl 3-O-allyl-4,6-O-benzylidene-1-thio-β-D-galactopyranoside 
• 400091-17-0 phenyl 3-O-allyl-1-thio-β-D-galactopyranoside 

Downstream Products

• 400091-21-6 phenyl 4-O-acetyl-3-O-allyl-6-O-benzyl-2-O-pivaloyl-1-thio-β-D-galactopyranoside 
• 400091-16-9 phenyl 3-O-allyl-6-O-benzyl-2-O-pivaloyl-1-thio-β-D-galactopyranoside 

Relevant academic research and scientific papers

Regioselective glycosylation of glucosamine and galactosamine derivates using O-pivaloyl galactosyl donors

Penta-O-pivaloyl-galactopyranose and tetra-O-pivaloyl-galactopyranosyl bromide after electrophilic activation reacted with 6-O-protected 2-azido-galactosides to give the precursor structures of the Thomsen-Friedenreich antigen disaccharide with high regioselectivity, but low yield. With 4,6-O-benzylidene protected 2-azidogalactosides and 2-O-pivaloyl phenylthio galactosides, T-antigen disaccharides of this type were obtained in good yields. Glycosylation reactions of 4,6-O-benzylidene protected glucosamine derivatives with O-pivaloyl protected galactosyl bromide efficiently gave lactolactosamine disaccharides. Even a thioglycoside was efficiently galactosylated by this method resulting in the formation of a disaccharide thioglycoside useful itself as a potential glycosyl donor.

Directed and efficient syntheses of β(1→4)-linked galacto-oligosaccharides

Straightforward, preparatively efficient procedures are described for the construction of β(1→4)-intergalactosidic linkages up to the hexasaccharide level. Key elements were the use of phenylthio and/or phenyl sulfoxide functionalities for glycosylations and a judiciously designed blocking group pattern for donor and acceptor alike: pivaloyl protection at O-2 for securing β-selectivity, sterically undemanding allyl or benzyl groups at O-3 and O-6 to minimise the steric bulk around the unreactive galactosyl-4-OH, the p-methoxyphenyl moiety, readily replaceable by SPh, as an intermediate anomeric substituent, and an acetyl group for temporary protection of the terminal Gal-4-OH. This strategy lends itself to iterative block synthesis and interchange of donors and acceptors, thereby demonstrating the broad scope and generality of the overall approach. Although predicted by molecular modelling, inclinations towards starch-like coiling could not so far be verified in any of the galacto-tetra-, -penta-, or -hexaoses or their p-methoxyphenyl glycosides.