Halogen addition to some 1-C-substituted pyranoid glycals

Levente Homolya; László Juhász; László Somsák

doi:10.1016/j.carres.2021.108292

Halogen addition to some 1-C-substituted pyranoid glycals

Carbohydr Res. 2021 Jun:504:108292. doi: 10.1016/j.carres.2021.108292. Epub 2021 Mar 19.

Authors

Levente Homolya¹, László Juhász¹, László Somsák²

Affiliations

¹ Department of Organic Chemistry, University of Debrecen, POB 400, H-4002, Debrecen, Hungary.
² Department of Organic Chemistry, University of Debrecen, POB 400, H-4002, Debrecen, Hungary. Electronic address: somsak.laszlo@science.unideb.hu.

PMID: 33940310
DOI: 10.1016/j.carres.2021.108292

Abstract

Addition of bromine and chlorine to O-peracylated 1-CN-, COOMe- and CONH₂-substituted glycals was studied under ionic and radical conditions. The main or exclusive products were the corresponding 2,3-trans-diaxial (3-bromo-3-deoxy-α-d-heptopyranosylbromide)onic acid derivatives. Bromination of the O-peracetylated d-lyxo-hept-2-enopyranosononitrile and all chlorinations proved selective towards the 2-axial-3-equatorial (3-halogeno-3-deoxy-α-d-heptopyranosylhalide)onic acid derivatives. Silver triflate promoted glycosylation of methanol was successful with each 2,3-trans-diaxial (3-bromo-3-deoxy-α-d-heptopyranosylbromide)onic acid derivative, however, several attempted nucleophilic substitution and elimination reactions gave the parent glycal only.

Keywords: 1-C-Substituted glycal; Glycosyl halide; Glycosylation; Halogen addition.

MeSH terms

Deoxy Sugars*
Glycosylation

Substances

Deoxy Sugars