Branched Homotrisaccharides

3 Branched Homotrisaccharides - P-D-Glc-(l- 2)-(P-D-Glc-(l- 3)]-a-D-Glc and the epimer P-D-Glc-(l- 2)-[P-D-Glc-(l- 3)]-a-D-Man have been prepared as a-methyl glycosides for conformational studies by NMR and Monte Carlo simulation methods.  

On treatment with NIS, TfOAg a mixture of the 2,6-tethered 6 and phenyl tetra-O-acetyl-l-thio-a-D-mannopyranoside underwent (l- 6)-cyclization of 6 and slower 3-a-mannosylation of the product, the former step being favoured by its intramolecular character in this one-pot procedure. a-D-Man-(l- 3)-[a-D-Man-(l- 6)]-a-D-ManOMe was consequently made in 30% yield. Alternatively this trisaccharide was made in 42% yield by direct selective mannosylation with the O-acetylated trichloroacetimidate (2 equiv) of p-nitrophenyl a-D-man-nopyranoside. The product was converted to the p-acrylamide glycoside and copolymerized with 2-acrylamido-N,iV-dimethylamine to give a product tested for lectin binding.  

Methyl 3,5-di-O-a-L-arabinofuranosyl-a-L-arabinofuranoside, which is the core unit of naturally occurring arabinans, has been described.  

---

Branched Homotrisaccharides.— By use of glycosyl dimethylphosphinothioate derivatives the branched mannotriose a-D-Maiip-(l- 6)-[a-D-Manp-(l->3)]-D-Man has been prepared. ... 

Branched Homotrisaccharides.-Ogawa has published on several compounds related to 2,3-di-0-o -D-mannopyranosyl-D-mannose, ° while Paulsen and Sinay have reported preparations of 3,6-disubstituted analogues. 

Branched Homotrisaccharides.—The 0-serine glycoside of 0-p-D-Gl( -(l- 3)-0-[ 3-D-Glcp-(l- 6)]-D-Glcp has been synthesised in connection with studies on the solid phase synthesis of glycopeptides. ... 

Branched Homotrisaccharides.- The four stereoisomers of methyl 4,6-di-Q-D-glucopyranosyl- -D-glucopyranoside with the a,a a,0 0,a and anomeric configurations were prepared with the pro-S C-6 proton replaced by a deuteron and used in the conformational analysis of the compovinds. " In contrast, prop-2-y1 3,6-di-Q- [a-D-mannopyranosyl]- -D-glucopyranoside was synthesized with each of the carbohydrate carbon-bonded protons replaced by deuterons. ... 

Trisaccharides Linear Homotrisaccharides Linear Heterotrlsaccharides Branched Homotrisaccharides Branched Heterotrisaccharides... 

---