reaction were elongated to β-oxo esters that were first reduced to β-hydroxy esters and then transformed into protected β-hydroxy aldehydes. Wittig–Horner–Emmons reaction with the anion of tetraisopropyl methylenebisphosphonate gave, after deprotection, the desired 4-hydroxy-6-purinyl- or -6-pyrimidinyl-1-hexenylphosphonic acids. A dimer, potential precursor of acyclic polynucleotides (APN), homomorphous with
已从 DNA 核碱基和
丙烯酸叔丁酯开始制备了以天然脱氧
核糖核苷酸为模型的无环卡巴核苷
膦酸酯。从迈克尔型反应获得的产物被延长为 β-氧代酯,该酯首先被还原为 β-羟基酯,然后转化为受保护的 β-羟基醛。Wittig-Horner-Emmons 与亚甲基
双膦酸四异
丙酯的阴离子反应,去保护后得到所需的
4-羟基-6-
嘌呤基-或-6-
嘧啶基-
1-己烯基
膦酸。还制备了一种二聚体,一种与 DNA 同形的无环多核苷酸 (A
PN) 的潜在前体。