SYNTHESIS OF 4-ACYL-1H-1,2,3-TRIAZOLIC NUCLEOSIDES

Abstract

Two simple regiospecific methodologies based on triazolic ring construction in the course of synthesis were applied for the synthesis of 1,2,3-triazolic nucleoside analogues. The cycloaddition reactions between diazomalonaldehyde and appropriate glycosylamine derivatives were rather effective, producing the desired nucleosides 11, 17 and 24. Diazotization of enamines 21a and 21b led to the corresponding triazolic ribonucleoside derivatives 22a and 22b, in good yields. Deprotection reaction of 22a, 22b and 24 was easily achieved by Lewis acid catalysis, producing the corresponding ribonucleosides 23a, 23b and 25.

ACKNOWLEDGMENTS

Fellowships granted to A.C.C. and L.O.R.P from CNPq (Brazil) and CAPES are gratefully acknowledged, respectively. M.C.B.V.S. and V.F.F. are grateful to CNPq for the individual research fellowships. We thank UNICAMP-IQ for MS spectra. We also thank Dr. Gilberto Alves Romeiro (Universidade Federal Fluminense, Brazil) and Dr. Alice Maria Rolim Bernardino (Universidade Federal Fluminense, Brazil) for useful advice. This work was partially supported by CNPq (National Council of Research from Brazil) and FAPERJ.