Influence of protecting groups on O- and C-glycosylation with neuraminyl and ulosonyl dibutylphosphates

Riku Ogasahara; Shuay Abdullayev; Vikram A Sarpe; Appi Reddy Mandhapati; David Crich

doi:10.1016/j.carres.2020.108100

Influence of protecting groups on O- and C-glycosylation with neuraminyl and ulosonyl dibutylphosphates

Carbohydr Res. 2020 Oct:496:108100. doi: 10.1016/j.carres.2020.108100. Epub 2020 Jul 28.

Authors

Riku Ogasahara¹, Shuay Abdullayev², Vikram A Sarpe³, Appi Reddy Mandhapati⁴, David Crich⁵

Affiliations

¹ Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA; Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan.
² Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA; Department of Chemistry, Université Claude Bernard Lyon 1, Domaine Scientifique de la Doua, boulevard du 11 Novembre 1918, 69622, Villeurbanne Cedex, France.
³ Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 West Green Street, Athens, GA, 30602, United States; Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602, United States.
⁴ Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA.
⁵ Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI, 48202, USA; Department of Pharmaceutical and Biomedical Sciences, University of Georgia, 250 West Green Street, Athens, GA, 30602, United States; Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602, United States; Department of Chemistry, University of Georgia, 140 Cedar Street, Athens, GA, 30602, United States. Electronic address: david.crich@uga.edu.

Abstract

The adamantanyl thioglycosides of 5-isothiocyano and 5-azido 5-desamino-4,7,8,9-tetra-O-acetylneuraminic acid methyl ester were converted into the corresponding dibutyl phosphates, which proved to be excellent α-selective donors for O-sialidation with a range of typical acceptors, and good donors for reaction with allyltributylstannane, albeit without significant anomeric selectivity. In the KDN series the dibuylphosphate derived from a donor carrying a 4,5-cyclic carbonate protecting group afforded the corresponding C-glycoside with excellent α-selectivity on activation in the presence of allyltributylstannane, whereas the corresponding donor carrying acetate esters at the 4- and 5-positions was unselective. Overall, it is revealed that while the strongly electron-withdrawing isothiocyanato and azido groups are sufficient to promote highly α-selective O-sialidation, they are inadequate when faced with less reactive nucleophiles when mixtures of anomers are obtained.

Keywords: C-Glycosides; Glycosyl phosphates; KDN C-Glycoside; Neuraminic acid; Sialidation.

MeSH terms

Carbon / chemistry*
Glycosylation
Oxygen / chemistry*
Phosphates / chemistry*
Stereoisomerism
Thioglycosides / chemistry

Substances

Phosphates
Thioglycosides
Carbon
Oxygen

Grants and funding

R01 GM062160/GM/NIGMS NIH HHS/United States