Syntheses and Structure Assignments of Six Azolinone Ribonucleosides

Article abstract of DOI:10.1021/jo00342a020

N-Ribosidation of a series of azolinones was achieved via silylation and SnCl4 catalysis.N-Ribosidation of 4-imidazolin-2-one gave 1-β-D-ribofuranosyl-4-imidazolin-2-one; of 1,2,4-triazolin-3-one gave 2- and 4-β-D-ribofuranosyl-1,2,4-triazolin-3-one, and 2,4-di-β-D-ribofuranosyl-1,2,4-triazolin-3-one; and of 2-tetrazolin-5-one gave 1-β-D-ribofuranosyl-2-tetrazolin-5-one and 1,4-di-β-D-ribofuranosyl-2-tetrazolin-5-one.Structure assignments were based on NMR and mass spectra, microanalytical data, and interconversions.The triazolinone monoriboside isomer structures were differentiated by ¹³C NMR long-range coupling patterns, and the assignments were confirmed by X-ray crystallography.New syntheses were developed for several of the ribonucleosides by fashioning the azolinone rings from 2,3,5-tri-O-benzoylribofuranosyl isocyanate.