title: Masked thiol sugars: chemical behavior and synthetic applications of S-glycopyranosyl-N-monoalkyl dithiocarbamates.
abstract: The chemical behavior of S-glycopyranosyl-N-monoalkyl dithiocarbamates (DTCs) as masked 1-glycosyl thiols, easily prepared by the nucleophilic displacement of 1-halo sugars with dithiocarbamate salts of primary amines, has been studied and synthetically exploited. This behavior relies on the abstraction of the proton of the carbamate functionality that allows controlled access to thiolate sugar intermediates. The basic character of the DTC salts used as reagents leads to thiolates that evolve in situ to symmetrical diglycosyldisulfides (DGDSs) when long reaction times are allowed. Alternatively, controlled unmasking of the thiolate function can be efficiently attained by treatment with an external base of isolated anomeric glycosyl DTCs, the formation of which is prevalent when using short reaction times. In this manner, a second methodology for the preparation of symmetrical DGDSs and a chemical protocol for the S-glycosylation of any electrophilic substrate are established. The applications of this last strategy for the preparation of thioglycosyl vinyl sulfones, thiodisaccharides, and S-linked homo- and heterodivalent neoglycoconjugates are described as a proof-of-concept of the great potential of the sugar DTCs in any chemical scenario in which the covalent attachment of a thiol sugar is required. The evaluation of the biological functionality of some divalent sulfurated sugar systems is also described.
authors.affiliation: Departmento de Q. Organica, Facultad de Ciencias, Insitituto de Biotecnología, Universidad de Granada, 18071 Granada (Spain), Fax: (+34) 958248437.
authors.forename: Alicia
authors.initials: A
authors.lastname: Megia-Fernandez
authors.forename: Diego
authors.initials: D
authors.lastname: de la Torre-Gonzalez
authors.forename: Jose
authors.initials: J
authors.lastname: Parada-Aliste
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Lopez-Jaramillo
authors.forename: Fernando
authors.initials: F
authors.lastname: Hernandez-Mateo
authors.forename: Francisco
authors.initials: F
authors.lastname: Santoyo-Gonzalez
mesh_terms: D001665:Binding Sites; D002219:Carbamates / Q000138:chemical synthesis / Q000737:chemistry*; D002241:Carbohydrates / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D037102:Lectins / Q000737:chemistry / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D002219:Carbamates; D002241:Carbohydrates; D006020:Glycopeptides; D037102:Lectins; D013438:Sulfhydryl Compounds; D006735:Horseradish Peroxidase
keywords: carbohydrates; dithiocarbamates; glycoconjugates; glycopeptides; glycoproteins