- Studies on Nucleosides and Nucleotides. VIII. Preparation and Reactions of Triphenylphosphoranediylnucleosides
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The reaction of uridine, N4-benzoylcitidine, guanosine, and N6-p-toluoyladenosine with diethyl azodicarboxylate and triphenylphosphine resulted in the formation of the corresponding 2',3'-O-(triphenylphosphoranediyl)cyclonucleosides.On the other hand, adenosine afforded, under similar conditions, 3',5'-O-(triphenylphosphoranediyl)adenosine (19).The difference can be explained in terms of the acidity of base moieties of the nucleosides.The reaction of 2',3'-O-(triphenylphosphoranediyl)-O2,5'-cyclouridine, N4-benzoyl-2',3'-O-(triphenylphosphoranediyl)-O2,5'-cyclocytidine, 2',3'-O-(triphenylphosphoranediyl)-N3,5'-cycloguanosine, or N6-p-toluoyl-2',3'-O-(triphenylphosphoranediyl)-N3,5'-cycloadenosine with nucleophiles and with electrophiles addorded the corresponding nucleoside derivatives with free 2'- and 3'-hydroxyl groups.Thus the 2',3'-O-triphenylphosphoranediyl group serves as a protecting group which is readily removed during work-up of the reaction products. 19 reacted with phenyl isocyanate to give 5'-O-phenylcarbamoyladenosine and N6,5'-O-bis(phenylcarbamoyl)adenosine.The reaction of 19 with diphenylketene also afforded acyladenosines with free 2'- and 3'-hydroxyl groups.These results suggested that 3',5'-O-triphenylphosphoranediyl group activates the 5'-carbon atom of adenosine.
- Kimura, Junji,Yagi, Kentaro,Suzuki, Hideyuki,Mitsunobu, Oyo
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p. 3670 - 3677
(2007/10/02)
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