Studies on tRNA and Related Compounds. XXXVII. Synthesis and Physical Properties of 2'- or 3'-O-(o-Nitrobenzyl) nucleosides : the Use of o-Nitrophenyldiazomethane as a Synthetic Reagent

Abstract

2'-and 3'-O-(o-Nitrobenzyl) derivatives of uridine, cytidine, adenosine and guanosine were synthesized by treatment of uridine, N-benzoylcytidine, N-benzoyladenosine and N-isobutyrylguanosine, respectively, with o-nitrophenyldiazomethane followed by isolation and deblocking. 3'-O-(o-Nitrobenzyl) guanosine is a novel compound. By using N-acylated nucleosides, separation of the 2'-and 3'-substituted isomers on silica gel became feasible and these compounds were useful intermediates for the synthesis of oligoribonucleotides. Some physical properties of these compounds were studied by ultraviolet, nuclear magnetic resonance, circular dichroism and the 2'-substituted isomers were found to have more stacked structures than the 3'-isomers.