Studies towards the synthesis of the hypermodified nucleoside of rat liver phenylalanine transfer ribonucleic acid: improved synthesis of the base beta-hydroxywybutine.
An improved synthesis of the key intermediates (3 and 8) for the synthesis of beta-hydroxywybutines [[R-(R*,S*)]- and [S-(R*,R*)]-4], the most probable structures for the minor base from rat liver tRNA(Phe), has been achieved by the Wittig reaction between 1-benzyl-7-formylwye (1) and the phosphorane derived from (R)-2-[(methoxycarbonyl)amino]-3-(triphenylphosphonio)propanoate (10), followed by methylation, OsO4 oxidation, and cyclocondensation with COCl2 in the presence of pyridine. The racemic forms of beta-hydroxywybutines [(R*,S*)- and (R*,R*)-4], which were required for the determination of the optical purity of [R-(R*,S*)]- and [S-(R*,R*)]-4 by means of chiral HPLC, were conveniently prepared through pyrolysis of the cyclic carbonate 3 followed by NaBH4 reduction and catalytic hydrogenolysis. The samples of [R-(R*,S*)]- and [S-(R*,R*)]-4 were thus shown to be optically pure.
Itaya
T
T
Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
Kanai
T
T
D000818:Animals; D006147:Guanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D008099:Liver / Q000378:metabolism; D009705:Nucleosides / Q000138:chemical synthesis*; D012360:RNA, Transfer, Phe / Q000138:chemical synthesis*; D051381:Rats; D013237:Stereoisomerism
D009705:Nucleosides; D012360:RNA, Transfer, Phe; C114501:hydroxywybutine; D006147:Guanine