241471-10-3

Upstream product

• 174172-99-7 ethyl 4,6-O-benzylidene-2-O-benzyl-1-deoxy-1-thio-β-D-glucopyranoside 
• 626-15-3 1,3-bis-(bromomethyl)benzene 

Downstream Products

• 744-05-8 methyl α-D-glucopyranosyl-(1->4)-α-D-glucopyranoside 
• 241471-12-5 methyl 6,3'-O-(1,3-xylylene)-(2-O-benzyl-4,6-O-benzylidene-α-D-glucopyranosyl)-(1'->4)-2,3-di-O-benzyl-α-D-glucopyranoside 
• 241471-11-4 ethyl 3-O-[3-(methyl 2,3-di-O-benzyl-α-D-glucopyranoside-6-yloxymethyl)-benzyl]-2-O-benzyl-4,6-O-benzylidene-1-thio-β-D-glucopyranoside 

Relevant academic research and scientific papers

Efficient Intramolecular Glycosylation Supported by a Rigid Spacer

The m-xylylene moiety was employed as rigid spacer in intramolecular glycoside bond formation. Fifteen-membered macrocycle formation starting from 6-O-linked donor and 6- and 4-O-linked acceptor (5a,b, 6b) led exclusively to β(1-4)- and β(1-6)-linked compounds 7β and 8β, respectively, which gave cellobioside and gentiobioside derivatives. The glycosylation yields could be improved by 14-membered macrocycle formation. In the four cases studied, the donor was 6-O-linked to the spacer. For the acceptor linkage to the spacer and the accepting hydroxy group, relative D-/L-threo- and D-/L-erythro-arrangements were chosen. Standard glycosylation conditions led in three cases (13, 14, 23) only to β-linkage in high yield (16β, 17β, 25β). For the transformation of 24, having a D-erythro-arrangement in the acceptor moiety, the α-anomer 26α was preferentially obtained. Limitation of the conformational space of the donor and the acceptor as in 31, which is stereochemically identical with 24, led to the corresponding α-glycoside 32α in 87% yield. Synthesis of a pseudo mirror image of 23 [having 6-(D)/3-(D-threo)-arrangement], namely 35, having 3(L)/6-(L-threo)-arrangement of the donor and acceptor moieties, expectedly gave only α-glycoside 36α in very high yield. Thus, the efficiency and versatility of this conceptual approach to intramolecular glycoside bond formation is exhibited.

Synthesis of trisaccharides and tetrasaccharides by means of intramolecular glycosylation supported by rigid spacers

Treatment of α,α′-dibromo-m-xylylene with 6-O-unprotected thiomaltoside 4 as glycosyl donor (→ 5), followed by 4-O-unprotected galactoside derivative 6 as acceptor, afforded β-linked macrocyclic trisaccharide 9β in high yield after removal of the 3-O-MPM protective group and subsequent intramolecular glycoside bond formation. Similarly, by the same sequence of steps, the corresponding tetrasaccharide 14β was obtained from 5 and 4b-O-unprotected lactoside 11. For reiterative glycoside bond formation, treatment of α,α′-dibromo-m-xylylene with 3-O-unprotected thioglycoside 15 as donor (→ 16), followed by 4,6-O-unprotected glucoside, and subsequent glycosylation afforded macrocyclic maltotrioside 22, which was transformed into known maltotrioside 23. A sight modification of the protecting-group pattern in maltotrioside synthesis resulted in generally higher yields in the ligation of the building blocks to the m-xylylene spacer, particularly in the second glycosylation step, thus providing macrocyclic maltotrioside 40α, which was transformed into known maltotriosides 41α and 41β.