摘要:
The preparation of the spacer-containing trimers 2, 3-aminopropyl 3-O-[4-O-Me-3-O-(4-N-D,L-lactoyl-3-O-Me-beta-D-Quip)-alpha-L-Rhap]-alpha-L-Rhap, derivatives of the antigenic determinant of the glycopeptidolipid from Mycobacterium avium serotype 12, are described. Thus, iodonium ion-mediated glycosylation of the spacer-containing acceptor 7 with ethyl 1-thio-rhamnopyranoside donor 10, followed try selective deprotection of the p-methoxybenzyl group of thus obtained 19 gave bis-rhamnopyranoside acceptor 20. Elongation of 20 with ethyl 4-azido-1-thio-beta-D-quinovopyranoside 18 and subsequent reduction of the azido function in 21 led to trimer 22. The amino group in 22 was coupled with both D- and L-lactic acid to give, after removal of the protective groups, trimers 2.