The Chemistry of C-Nucleosides

Highly regioselective 1,3-dipolar cycloaddition of 3′-O-propargyl guanosine with nitrile oxide: An efficient method for the synthesis of guanosine containing isoxazole moiety

“…The data show that there is no nuclear overhauser effect (NOE) signal between one of the C5 methylene protons and ortho proton of the phenyl ring present in the isoxazole moiety ( Figure 1 ). The other possible 3,4-disubstituted regioisomer 6a was not detected in the 1 H NMR spectrum of the crude reaction mixture ( Figure 2 ). Scheme 1 .…”

“…The nucleic acid chemistry has been the subject of immense interest in the area of medicinal chemistry as the nucleotides serve as a versatile building blocks for both DNA and RNA synthesis as well as involve in numerous critical biological process. [1] , [2] It has been well documented in the literature that there are several approved drugs on the market containing nucleoside/nucleotide analogs have been used for the treatment of cancers, parasites, bacterial, viral and fungal infections. [3] , [4] Notably, these analogs represent the unique class of antiviral drugs for various viruses such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), influenza virus, respiratory syncytial virus (RSV), hepatitis B virus (HBV), human papillomavirus (HPV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), and varicella-zoster virus (VZV).…”

“…The 1,3-dipolar cycloaddition is highly regioselective affording exclusive 3,5-disubstituted isoxazole 5a . The structure of 5a was ascertained by 1 H and 13 C NMR and mass spectral data. The regiochemistry of 5a was unequivocally established by typical NOESY NMR techniques.…”

De Novo Syntheses of Racemic Deoxy-C-nucleosides

“…C-Nucleosides have demonstrated potential as anticancer and anti-HIV agents . These compounds mimic the action of regular nucleosides; however, the replacement of a C−N with a C−C linkage in C-nucleosides provides these compounds with impressive oral bioavailablities and therapeutic lifetimes.…”

A Versatile Protocol for theSynthesis of Oxazole and 3-Nitro/3-Carbethoxy PyrroleC-Nucleosides using TOSMIC

“…Ever since the discovery of pseudouridine in nature in 1957, 2 a considerable number of C-nucleosides have been synthesized and have found application as antibiotics and potential anti-cancer and/or anti-viral agents. 3 Accordingly, base analogs designed to function as wild card in base pairing within nucleic acids duplexes have been sought. The search for a 'universal base' has been intensive in recent years, 4 as these would be of significant use for the construction of nucleic acid probes and primers where the identity of the base in the target nucleic acid is unknown.…”