An Approach to the Synthesis of Four Rhodomicrobium Vannielii Lipid a Analogues
Titel:
An Approach to the Synthesis of Four Rhodomicrobium Vannielii Lipid a Analogues
Auteur:
Westerduin, P. Beetz, T. Dees, M. J. Erkelens, C. Smid, P. Zuurmond, H. Van Boeckel, C. A. A. Van Boom, J. H.
Verschenen in:
Journal of carbohydrate chemistry
Paginering:
Jaargang 7 (1988) nr. 3 pagina's 617-644
Jaar:
1988-09-01
Inhoud:
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.