Synthesis of the Rat Brain Thy-1 GPI Anchor

SCHEME 13.7 Fraser-Reid s synthesis of building blocks for the convergent assembly of the rat brain Thy-1 GPI anchor. DMAP, 4-dimethylaminopyridine PPTS, pyridinium 

The Schmidt group reported another synthesis of rat brain Thy-1 GPI in 1999 [52], In 2003, they reported a rather similar synthesis [53] that involved differentially protected phosphoethanolamine groups useful for future regioselective protein/ peptide coupling reactions. This differentiation was made possible by using Cbz and te/t-butoxycarbonyl (Boc)-protected phosphoramidite reagents that could be 

SCHEME 13.10 Completion of Schmidt s synthesis of rat brain Thy-1 GPI with differentiated phosphoethanolamine moieties. 

Bn groups and Cbz protection, under which condition the amino Boc protection is stable. GPI 74 is the first fully phosphorylated synthetic GPI that was feasible for future coupling with peptides or proteins. 

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In another synthesis of the rat brain Thy-1 GPI anchor, Schmidt and coworkers [88] have adopted the linear strategy to construct the pentasaccharide building block. As shown in O Scheme 11, after all monosaccharide units were obtained, they were assembled sequentially by the trichloroimidate glycosylation method to form pentasaccharide 130. It was manipulated... 

A variable concept for the synthesis of branched glucosyl phosphatidyl inositol (GPI) anchors was established. Its efficiency could be shown by the successful synthesis of the GPI anchor of rat brain Thy-1 (49), and of the scrape prion protein (Figure 10). ... 

Udodong UE, Madsen R, Roberts C, Fraser-Reid B. A ready, convergent synthesis of the heptasaccharide GPI membrane anchor of rat brain Thy-1. J Am Chem Soc 1993 115 7886-7887. 

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