2′-Modified Neamine Analogues from Thiomannosides through Glycosidation-Stereoinversion

• Published in: European journal of organic chemistry 2012-09, Vol.2012 (25), p.4740-4750
• Main Authors: Gironés, Daniel, Hanckmann, Marcel, Rutjes, Floris P. J. T., van Delft, Floris L.
• Format: Article
• Language: English
• Subjects: Carbohydrates; Carbohydrates with 4, 5, 6, ... C atoms, dissacharides and oligosaccharides; Carbohydrates. Nucleosides and nucleotides; Chemistry; Exact sciences and technology; Glycosidation; Heterocyclic compounds; Heterocyclic compounds with o, s, se, te hetero atom and condensed derivatives; Organic chemistry; Organometalloidal and organometallic compounds; Oxidation; Oxygen heterocycles; Preparations and properties; Reduction; Si derivatives
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201200084

Conveniently protected neamine analogues were synthesized with a free 2′‐OH group for further functionalization. An approach was investigated involving a stereoselective α‐glycosidation reaction of 3,4‐O‐dimethoxybutanediyl‐2‐O‐silyl protected thiomannosides with a 2‐deoxystreptamine derivative. Subsequent 2‐O‐deprotection followed by anoxidation–reduction sequence led to α‐glucosides withstereoinversion at C‐2′. The scope of the procedure for the syntheses of α‐glucosides was explored with three distinct model acceptors. Thiomannoside coupling, 2‐O‐deprotection, and oxidation were straightforward, whereas the outcome of the reduction step was clearly acceptor‐dependent. Neamine analogues with a free 2′‐OH group were synthesized through a stereoselective α‐glycosidation reaction of 3,4‐O‐dimethoxybutanediyl‐2‐O‐silyl‐protectedthiomannosides, followed by a 2‐O‐deprotection and an oxidation–reduction sequence, leading to stereoinversion at C‐2′. The scope of such a procedure for the syntheses of α‐glucosides was explored with three distinct model acceptors.