Studies towards the Synthesis of the Fluorescent Bases of Phenylalanine Transfer Ribonucleic Acids : Synthesis of 7-(2-Hydroxy-3-methylbutyl)wye, a Model for the Minor Base Isolated from Rat Liver

概要

論文の詳細を見る
Treatment of 1-benzyl-7-(hydroxymethyl)wye (8) with PBr_3 in the presence of Ph_3P gave the phosphonium bromide 9 in good yield, Heating 9 and Me_2 CHCHO (7) in MeOH in the presence of K_2CO_3 provided 1-benzyl-1,4-dihydro-4,7-dimethyl-6-(3-methyl-1-butenyl)-9H-imidazo[1,2-a]purin-9-one (11), a positional isomer of the objective 1-benzyl-7-(3-methyl-1-butenyl)wye (5), as a major product. When the reaction was conducted in Me_2NCHO at -65℃ using n-BuLi as base, a 7 : 2 mixture of (E)-and (Z)-5 was obtained in good yield. Nevertheless, neither the protected amino aldehyde 18 nor 21 gave the desired olefin under similar conditions, implying poor applicability of this method to the synthesis of the fluorescent bases of phenylalanine transfer ribonucleic acids (tRNAs^<Phe>).Compound 5 was alternatively synthesized by the Wittig reaction between 1-benzyl-7-formylwye (3) and Ph_3P^+CH_2CHMe_2 I^- (4) in tetrahydrofuran as an equimolar mixture of the geometrical isomers in 50% yield. When the reaction was carried out in Me_2SO at room temperature using two equivalents each of NaCH_2SOMe and 4,the product, obtained in high yield, was (E)-11. The use of an equimolar amount of the base afforded (E)-5 in 26% yield. Oxidation of (E)-5 with OsO_4 followed by hydrogenolysis over Pd-C gave 7-(2-hydroxy-3-methylbutyl)wye (2), a model for the minor base from rat liver tRNA.^<Phe>.
公益社団法人日本薬学会の論文
1989-05-25