T. Buskas et P. Konradsson, Synthesis of oligosaccharides designed to form micelles, corresponding to structures found in ovarian cyst fluid, J CARB CHEM, 19(1), 2000, pp. 25-51
The syntheses of alpha-D-GlcpNAc-(1-->4)-beta-D-Galp-(1-->4)-beta-D-GlcNAc-
(1-->O)-(CH2)(15)CH3 (1) and fragments thereof, corresponding to structures
found in human ovarian cyst fluid, are described. Silver triflate promoted
coupling of 3.4,6-tri-O-acetyl-2-azido-2-deoxy-beta-D-glucopyranosyl bromi
de (12) and galactose acceptor (11) gave a disaccharide donor (13), which w
as readily transformed into the corresponding bromo-derivative 18. For the
synthesis of disaccharide beta-D-Galp-(1-->4)-D-GlcNAc, several differently
protected glucosamine accepters were prepared. It was found that cetyl alc
ohol needed to be introduced after the formation of the P-galactoside bond.
Glycosylation of pent-4-enyl 3,6-di-O-benzyl-2-deoxy-2-tetrachlorophthalim
ido-beta-D-glucopyranoside (30) with (3,4,6-tri-O-acetyl-2-azido-2-deoxy-al
pha-D-glucopyranosyl)-(1-->4)-2,3,6-tri-O-benzoyl-alpha-D-galactopyranosyl
bromide (18) by use of silver triflate as promoter gave the desired trisacc
haride 31. Finally 31 was transformed via coupling to the long alkyl chain
aglycon and deprotection into the title compound 1.