title: Access to piperidine imino-C-glycosides via stereoselective thiazole-based aminohomologation of pyranoses.
abstract: The access to piperidine homoazasugars (dideoxyiminoheptitols) from pyranoses via formal one-carbon chain elongation and exchange of the ring oxygen with the NH group is described. The key process involves the stereoselective addition of 2-thiazolylmagnesium bromide to an N-glycosylhydroxylamine, i.e., a hidden open-chain sugar nitrone. The N-thiazolylalkylhydroxylamine formed in this way is reduced to amine, and this transformed into a substituted piperidine via intramolecular cyclization by an S(N)2 process. Cleavage of the thiazole residue attached to C2 of the piperidine ring reveals the formyl group, and this is reduced to hydroxymethyl to give the target homoazasugar. A collection of six stereodiversified compounds with free OH and NH groups and isolated as hydrochlorides has been prepared.
authors.affiliation: Dipartimento di Chimica, Laboratorio di Chimica Organica, Università di Ferrara, Via L. Borsari 46, 44100 Ferrara, Italy. adn@unife.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Dondoni
authors.forename: Andrea
authors.initials: A
authors.lastname: Nuzzi
mesh_terms: D000588:Amines / Q000737:chemistry; D006027:Glycosides; D050111:Imino Sugars / Q000138:chemical synthesis*; D009005:Monosaccharides / Q000138:chemical synthesis*; D010880:Piperidines / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013844:Thiazoles / Q000737:chemistry
chemical_list: D000588:Amines; C438934:C-glycoside; D006027:Glycosides; D050111:Imino Sugars; D009005:Monosaccharides; D010880:Piperidines; D013844:Thiazoles; C032727:piperidine