摘要:
The disaccharide alpha-D-GlcNAcp-(1-5)-beta-KDO-2-OCH2CH2CH2NH2 containing a spacer beta-linked to KDO is prepared via iodonium ion-assisted glycosylation of a suitable KDO acceptor with ethyl 2-azido-2-deoxy-3,4-di-O-benzyl-1-thio-alpha/beta-D-glucopyranoside. The key KDO building unit is synthesized in 7 steps starting with 2,3:5,6-di-O-isopropylidene-D-mannitol.