321896-01-9

Upstream product

• 18162-48-6 tert-butyldimethylsilyl chloride 
• 259882-15-0 allyl 4,6-O-benzylidene-D-glucopyranoside 
• 321896-09-7 allyl 4,6-O-benzylidene-2-O-pivaloyl-α-D-glucopyranoside 
• 93382-48-0 allyl 4,6-O-benzylidene-α-D-glucopyranoside 
• 321896-10-0 allyl 4,6-O-benzylidene-3-O-tert-butyldimethylsilyl-2-O-pivaloyl-α-D-glucopyranoside 

Downstream Products

• 685104-39-6 allyl 2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl-(1->2)-4,6-O-benzylidene-3-O-tert-butyldimethylsilyl-α-D-glucopyranoside 
• 685104-21-6 allyl 4-O-acetyl-6-O-triphenylmethyl-2-O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-α-D-glucopyranoside 
• 685104-40-9 C₇₃H₇₀O₂₂ 
• 685104-23-8 tert-butyl [allyl 4-O-acetyl-2-O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-α-D-glucopyranoside]uronate 
• 685104-19-2 allyl 4,6-O-benzylidene-2-O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-α-D-glucopyranoside 
• 685104-24-9 tert-butyl [4-O-acetyl-2-O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-α-D-glucopyranoside]uronate 
• 685104-22-7 allyl 4-O-acetyl-2-O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-α-D-glucopyranoside 
• 685104-20-5 allyl 2-O-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl)-3-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-α-D-glucopyranoside 
• 685104-18-1 allyl 2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl-(1->2)-4,6-O-benzylidene-α-D-glucopyranoside 

Relevant academic research and scientific papers

Protecting Group Dependence of Stereochemical Outcome of Glycosylation of 2-O-(Thiophen-2-yl)methyl Ether Protected Glycosyl Donors

A series of glycosyl donors possessing a (thiophen-2-yl)methyl ether protecting group at position 2 were synthesised and the effect of the protecting group pattern of other hydroxyls on the stereochemical outcome of glycosylation was investigated. Studies revealed optimal α-selectivity for glycosylation using a fully armed tri-benzylated donor, whilst other protecting group patterns were significantly less effective. Low-temperature NMR studies of both fully armed and fully disarmed donors revealed the intermediacy of cyclised sulfonium ion intermediates. Reaction conditions were developed which allowed removal of the (thiophen-2-yl)methyl ether protecting group either selectively, or together with benzyl ethers. Glycosyl donors with a 2-O-thiophenylmethyl ether protecting group undergo six-membered ring NGP, as demonstrated by low-T NMR studies, but the stereochemical outcome of glycosylation is highly dependent on other protecting groups.

Synthesis of the trisaccharide and tetrasaccharide moieties of the potent immunoadjuvant QS-21

The title trisaccharide and tetrasaccharide moieties have been synthesized as part of our research programme to construct the complex triterpenoid saponin QS-21, a potent immunoadjuvant, which has been used in a series of clinical immunization trials. In view of the unwillingness of glucuronic acid as glycosyl acceptor, the branched glucuronic acid-containing trisaccharide 20 was synthesized from D-glucose, which was in turn glycosylated at positions 2 and 3, followed by oxidation at position 6, in a linear sequence of 15 steps and in good overall yield. The apiose-containing tetrasaccharide 36 was constructed by a linear glycosylation strategy from the non-reducing terminal sugar, D-apiose, which was prepared from D-xylose by a known procedure, also in a linear sequence of 15 steps. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Rearrangement of sugar 1,2-orthoesters to glycosidic products: A mechanistic implication

The identification of cross-over products in the rearrangement of two structurally similar sugar 1,2-orthoesters to glycosidic products is reported.