28782-67-4Relevant academic research and scientific papers
High-throughput five minute microwave accelerated glycosylation approach to the synthesis of nucleoside libraries
Bookser, Brett C.,Raffaele, Nicholas B.
, p. 173 - 179 (2007/10/03)
The Vorbrueggen glycosylation reaction was adapted into a one-step 5 min/130 °C microwave assisted reaction. Triethanolamine in acetontrile containing 2% water was determined to be optimal for the neutralization of trimethylsilyl inflate allowing for direct MPLC purification of the reaction mixture. When coupled with a NH3/methanol deprotection reaction, a high-throughput method of nucleoside library synthesis was enabled. The method was demonstrated by examining the ribosylation of 48 nitrogen containing heteroaromatic bases that included 25 purines, four pyrazolopyrimidines, two 8-azapurines, one 2-azapurine, two imidazopyridines, two benzimidazoles, three imidazoles, three 1,2,4-triazoles, two pyrimidines, two 3-deazapyrimidines, one quinazolinedione, and one alloxazine. Of these, 32 yielded single regioisomer products, and six resulted in separable mixtures. Seven examples provided inseparable regioisomer mixtures of -two to three compounds (16 nucleosides), and three examples failed to yield isolable products. For the 45 single isomers isolated, the average two-step overall yield ± SD was 26 ± 16%, and the average purity ± SD was 95 ± 6%. A total of 58 different nucleosides were prepared of which 15 had not previously been accessed directly from glycosylation/deprotection of a readily available base.
Efficient synthesis of 2′-C-β-methylguanosine
Li, Nan-Sheng,Piccirilli, Joseoh A.
, p. 4018 - 4020 (2007/10/03)
2′-β-Methyl nucleosides have potential value as therapeutic agents and as nucleoside analogues for exploring RNA biology. Here we develop a strategy for efficient synthesis for 2′-C-β-methylguanosine (3). Starting from 1,2,3,5-tetra-O-benzoyl-2-C-β-methyl
The synthesis of [(β-D-ribofuranosyloxy)-methyl]nucleosides
Mereyala, Hari Babu,Mamidyala, Sreeman Kumar
, p. 655 - 669 (2007/10/03)
The coupling reaction of acetoxymethoxy ribofuranoside 4 with nucleic acid bases 5a-f to synthesize novel (ribofuranosyloxy)methyl uracil, thymine, cytosine, adenine, guanine derivatives 6a-g respectively in preference to the expected formation of natural nucleosides 2′,3′,5′ -tri-O-benzoyl uridine, methyluridine, cytidine, adenosine and guanosine 7a-g is described. Detailed study of these reactions catalysed by Lewis acids TMSOTf and SnCl4 is described. TMSOTf exhibited selectivity for the formation of ribofuranosyloxy methyl derivatives 6a-g rather than 7a-g. Reason for formation of 6a-g is explained by HSAB principle.
A Regiocontrolled Synthesis of N7- and N9-Guanine Nucleosides
Garner, Philip,Ramakanth, Sarabu
, p. 1294 - 1298 (2007/10/02)
The reaction of 2-O-acetylated and 2-O-benzoylated glycosides 3a,b/4a,b with silylated N2-acetylguanine 7 selectively gave N7-guanine nucleosides 8a,b/9a,b under kinetically controlled conditions (SnCl4/CH3CN, room temperature), whereas 2-O-benzoylated glycosides 3b/4b selectively gave isomeric N9-guanine nucleosides 10b/11b under termodynamically controlled conditions (TMSOTf/(CH2Cl)2, reflux).Unambiguous assignment of nucleoside structure was accomplished after hydrolysis (NH3/MeOH) of the initial products to the known nucleosides 8c, 9c, 10c, and 11c followed by 1H NMR and 13C NMR spectral analysis.The described procedures provide the best method to date for the selective synthesis of either N7- or N9-guanine nucleosides from a common substrate.
