A convenient synthesis of antiviral acyclic C-nucleosides incorporating 1,3,4-thiadiazine nucleus as a nucleobase

摘要

Adducts 4a-d obtaine by nucleophilic addition of sulphenylated dimethyl sulphoxide derivatives 2a,b to glucose thiosemicarbazones 3a,b undergo intramolecular cyclisation, involving methanesulphinyl leaving group, with 90 H_2SO_4 and Pummerer rearrangement with glacial acetic acid to yield acyclic C-nucleosides, 2-arylamino-6-(5-aryl-1,3,4-thiadiazol-2-ylthio)-5-(D-glucopentyl)-4H,5,6-dihydro-1,3,4-thiadiazines 6a-d and 2-arylamino-6-(5-aryl-1,3,4-thiadiazol-2-ylthio)-5-(D-glucopentyl)-6-methylthio-4H,5,6-dihydro-1,3,4-thiadiazines 7a-d, respectively.