Influence of substitution at the 5α-Position on the side chain conformation of glucopyranosides. (February 2021)

• Record Type: Journal Article
• Authors: Rajasekaran, Parasuraman; Pirrone, Michael G.; Crich, David
• Is Part Of: Carbohydrate research. Volume 500(2021)
• Publication Date: 2021-02
• Subjects: Conformational analysis; Carbohydrates -- Periodicals; Chemistry, Organic -- Periodicals; Biochemistry -- Periodicals; Carbohydrates -- Periodicals; Chimie organique -- Périodiques; Glucides -- Périodiques; Biochemistry; Carbohydrates; Chemistry, Organic; Periodicals; Electronic journals; 507.78
• DOI: 10.1016/j.carres.2021.108254
• Languages: English
• ISSNs: 0008-6215

Abstract

Abstract: We describe the preparation of methyl 5α-methyl-α-d -glucopyranoside and of 5α-fluoro-β-d -glucopyranose per acetate and the NMR-based conformational analysis of their side chains. Both the 5α-methyl and 5α-fluoro substituents increase the population of the gauche, gauche side chain conformer to the extent that it becomes the predominant conformation. In the 5α-methyl series this is attributed to steric effects, whereas in the 5α-fluoro series the optimization of attractive gauche effects is the more likely reason. Graphical abstract: Image 1 Highlights: Side chain conformation analysis of 5α-susbtituted glucopyranose derivatives. A 5α-methyl group strongly favors the gg side chain conformation of glucopyranosides. A 5α-fluoro substituent strongly favors the gg side chain conformation of glucopyranosides.