1-(2,3-O-Cyclohexylidene-4-C-hydroxymethyl-α-L-lyxofuranosyl)uracil (1) was converted in seven steps into 1-(2-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (8) and further into 1-(2-deoxy-4-C-hydroxymethyl-3,5-O-isopropylidene-α-L-threo-pentofuranosyl)uracil (9). Successive benzoylation, removal of the isopropylidene group, reaction with acetaldehyde diethyl acetal, and debenzoylation afforded (R)- and (S)-1-(2-deoxy-3,5-O-ethylidene-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)uracil (10a and 10b, respectively). Reaction of 1-(2-deoxy-4-C-triphenylmethyloxymethyl-α-L-threo-pentofuranosyl)uracil (14) with dichloromethane under conditions of phase transfer, followed by detritylation, afforded 1-(2-deoxy-4-C-hydroxymethyl-3,5-O-methylidene-α-L-threo- pentofuranosyl)uracil (15). Compound 14 was obtained from the derivative 8 by partial silylation, tritylation and desilylation. The absolute configuration of the isomeric ethylidene derivatives 10a and 10b was determined by NMR spectroscopy and the population of the deoxypentofuranose ring conformers was derived from the vicinal coupling constants J(H,H). The obtained results were compared with energy calculations. Neither of the prepared nucleoside analogues was active in vitro against HIV-1 and HIV-2.
1-(2,3-环己基甲酰基-4-C-羟甲基-α-L-吕克索呋喃核苷)(1)被转化为1-(2-脱氧-4-C-羟甲基-α-L-反式-戊糖呋喃核苷)(8),并进一步转化为1-(2-脱氧-4-C-羟甲基-3,5-O-异丙基-α-L-反式-戊糖呋喃核苷)(9),共经过七步。连续苯甲酰化,去除异丙基基团,与乙醛二乙醇缩醛反应,去苯甲酰基,得到(R)和(S)-1-(2-脱氧-3,5-O-乙基烯基-4-C-羟甲基-α-L-反式-戊糖呋喃核苷)(10a和10b)。1-(2-脱氧-4-C-三苯甲氧基甲基-α-L-反式-戊糖呋喃核苷)(14)与二氯甲烷在相转移条件下反应,随后去三苯甲基基团,得到1-(2-脱氧-4-C-羟甲基-3,5-O-甲基亚甲基-α-L-反式-戊糖呋喃核苷)(15)。化合物14由衍生物8部分硅化,三苯甲基化和去硅化得到。异构乙烯基衍生物10a和10b的绝对构型由NMR光谱确定,去氧核糖环构象的种群从邻近偶合常数J(H,H)中得出。所得结果与能量计算进行比较。制备的两种核苷类似物在体外对HIV-1和HIV-2均不活性。