P. Westerduin

Synthesis of the fragment GlcNAc-α(1→p→6)-GlcNAc of the cell wall polymer of staphylococcus lactis having repeating N-acetyl-D-glucosamine phosphate units

Abstract The monofunctional phosphitylating reagents chloro-β-cyanoethyl-N,N-diisopropylamino-phosphoramidite ( 3 ) and salicylchlorophosphite ( 4 ) have been applied towards the introduction of an α(1→6) interglycosidic phosphodiester bond between two properly-protected N-acetyl-D-glucosamine units. Evidence will be presented to show that 4 gives a higher yield of the required dimer than 3 .

An approach to the synthesis of α-l-fucopyranosyl phosphoric mono- and diesters via phosphite intermediates

Abstract The reagent chloro-β-cyanoethyl-N,N-diisopropylamino-phosphoramidite reacts smoothly with the anomeric hydroxyl group of a properly protected (benzyl) α-L-fucopyranose to afford a relatively stable phosphite intermediate in high yield. The latter can easily be converted into valuable α-L-fucopyranosyl phosphoric mono- and diesters.

Preparation of a fragment of the cell wall teichoic acid of Bacillus licheniformis ATCC 9945 via a solid phase approach

Abstract The phosphodiester bond between C-3OH and C-6′OH of the glycerol and galactose moieties of the repeating unit 1-0-[β-D-galactopyranosyl]glycerol of a teichoic acid of a Bacillus organism was introduced via a phosphite-triester approach. The elongation process could be realized by adopting a solid-support method, to give, after deblocking, a teichoic acid fragment having four phosphodiester linkages.

Chemical synthesis of diphosphorylated lipid a derivatives

Abstract The application of two new phosphorylation procedures enabled us to synthesize an analog of Lipid A.

Synthesis of 2,3-di-O-phytanyl-1-O-[glucosyl (galactosyl)-β(1→6) -mannosyl-α(1→2)-glucosyl-α (1→1)]-SN-glycerol. Purple membrane glycolipids

Abstract A convenient approach to the synthesis of triglycosyl-2,3-di-O-phytanyl-sn-glycerols will be presented. Special attention will be paid to the use of the following protective groups in carbohydrate chemistry: the 2,2,2-trichloroethoxycarbonyl, the 1,1,3,3-tetraisopropyldisiloxane-1,3-diyl and the o-dibromomethyl benzoyl group.

An Approach to the Synthesis of Four Rhodomicrobium Vannielii Lipid a Analogues

Abstract The preparation of four Rh. Vannielii Lipid A analogues (i.e. compounds 22, 23, 30 and 33) is described. Non-neighbouring group supported introduction of the β-glycosidic linkages was performed by coupling the mannopyranosyl bromide 2 and the 2-azido-2-deoxy-glucopyranosyl bromides 10 and 13 with the suitably protected glycosyl acceptors 3, 4 and 5 in the presence of a heterogeneous silver catalyst, to give compounds 6, 7, 14 and 24, respectively. Selective removal of the ally1 group and reduction of the azido functions followed by several O,N-acylation steps afforded, after complete deblocking, the tri-and disaccharide Rh. Vannielii Lipid A analogues 22, 23, 30 and 33.