A novel glycosyl donor for synthesis of 2-acetamido-4-amino-2,4,6-trideoxy-α-D-galactopyranosides.
2-Azido-4-benzylamino-4-N-,3-O-carbonyl-2,4,6-trideoxy-d-galactopyranosyl trichloroacetimidate (14) was conveniently prepared in six steps by regioselective introduction of an N-benzyl carbamate at O-3 of 6-deoxy-d-glucal 6, followed by mesylation at O-4. Intramolecular displacement of the leaving group afforded oxazolidinone 11. Azidonitration of the bicyclic glycal 11 gave the glycosyl nitrate anomers 12 in good yield and stereoselectivity. Hydrolysis of the anomeric nitrates under aqueous conditions gave the pyranose 13, which was easily converted into the imidate 14. Glycosylation of cyclohexanol by 14 gave glycosides 16α and 16β in a ratio of 4:1.
Iynkkaran
Ithayavani
I
Alberta Ingenuity Centre for Carbohydrate Science and Department of Chemistry, The University of Alberta, Gunning-Lemieux Chemistry Centre, Edmonton, AB, Canada T6G 2G2.
Bundle
David R
DR
D005688:Galactosamine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006027:Glycosides / Q000737:chemistry*; D006031:Glycosylation; D006868:Hydrolysis; D015394:Molecular Structure; D013237:Stereoisomerism
D006027:Glycosides; D005688:Galactosamine