Oxazoline glycosyl donors

Oxazoline glycosyl donors are generally prepared from the corresponding 2-acylamido-2-deoxyglycosides by the activation of the C-l leaving group using an... 

The preparation of several glucofuran [2, l-t/] oxazolines 35 and 36 from reaction of 2-amino-2-deoxy-D-glucose 34 with HF has been described. Compounds 35a and 35b are formed when the reaction is carried out in formic acid, whereas the orthoesters 36a-c are formed when the reaction is carried out using anhydrides. Further reaction of 35 and 36 with methanol gives methyl glycosides. Thus, 35 and 36 may hnd use as potential glycosyl donors for the synthesis of 2-amino-2-deoxy sugars (Scheme 8.14). " ... 

Aminosugars can be activated by formation of the corresponding trichloro-oxazolines, which are excellent glycosyl donors as they form disaccharides with good trans selectivity under mild conditions <03OL4995>. 

Kobayashi, S., Kiyosada, T., and Shoda, S. (1997) A novel method for synthesis of chitobiose via enzymatic glycosylation using a sugar oxazoline as glycosyl donor. Tetrahedron Lett., 38, 2111-2112. 

The ureido-compounds (20) gave the oxazolines (21) on treatment with tin tetrachloride, the latter being glycosyl donors. An alternative route to a- or /3-gIycosides in this series is illustrated in Scheme 2. The selectivity is extremely high and depends... 

The methyl oxazoline of 3,4,6-tri-O-acetyl-D-glucosamine was used as a glycosyl donor in the glycosylation of allyl 6-0-pivaloyl-P-D-galactopyranoside the reaction took 3-4 days in the presence of BF3 OEtj and afforded the P-(l—>3)-disaccharide as the only regioisomer in 45-50% yield [139],... 

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