An Efficient Route to Pyrimidine Nucleoside Analogues by [4 + 2] Cycloaddition Reaction
作者:Morwenna S. M. Pearson、Aélig Robin、Nathalie Bourgougnon、Jean Claude Meslin、David Deniaud
DOI:10.1021/jo034709a
日期:2003.10.1
synthesis for pyrimidine nucleoside analogues by [4 + 2] cycloaddition reaction. These compounds were obtained by convergent chemistry from glycosyl isothiocyanates 3a-f (pyranoses, furanoses, and dissaccharides) and diazadienium salt 5. In fact, diazapentadienium iodide 5 prepared from vinylthioamide 4 is an efficient intermediate in heterocyclic synthesis and reacts with isothiocyanates 3a-f affording
Chiral thioxohydroimidazoles with two sugar moieties. N-, C-, and spiro-nucleosides
作者:Consolación Gasch、M.Angeles Pradera、Bader A.B Salameh、José L Molina、José Fuentes
DOI:10.1016/s0957-4166(99)00550-9
日期:2000.2
2-Amino (alkyl and arylamino)-2-deoxy-D-fructose and different sugar isothiocyanates are used in the diastereoselective synthesis of chiral imidazolidine-2-thione hi-nucleosides 12-23. Water beta-elimination of these compounds produces imidazoline-2-thione N-nucleosides 27-31, whereas cyclodehydration of the same products gives, with high stereoselectivity, chiral spironucleosides with an N-glycosyl radical 34-37. Conformational aspects of some of the prepared compounds are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.