Experimental observations on the reductive cleavage of endo and exo 3, 4-O-benzylidene fucopyranoside derivatives. (July 2021)

• Record Type: Journal Article
• Authors: Studzian, Maciej; Pérez, María-Elena; Arias-Pérez, María-Selma
• Is Part Of: Carbohydrate research. Volume 505(2021)
• Publication Date: 2021-07
• Subjects: Fucopyranosides -- 3, 4-O-benzylidene acetals -- Reductive opening -- Regioselectivy -- Brönsted acid activation -- Bu2BOTf; 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.2021.108338
• Languages: English
• ISSNs: 0008-6215

Abstract

Abstract: Reductive cleavage of methyl 3, 4- O -benzylidene-α-L-fucopyranosides with BH3 ·THF-TfOH and NaCNBH3 -TfOH systems resulted in enhanced reaction rates and selectivity compared to BH3 ·THF-Bu2 BOTf. With this latter system, the nature of the O -2 substituent exerted a clear control on the reactivity but practically did not affect the regioselectivity. With TfOH the direction of cleavage was determined, as expected, by the configuration of the acetal carbon atom, but slightly influenced by its competitive epimerization. Protic conditions provided higher regioselectivity in the openings of the exo isomers, affording a useful approach to the practical synthesis of 3- O -benzyl ethers. Graphical abstract: Image 1