Stereoselective Approach to the<i>Z</i>-Isomers of Methylenecyclopropane Analogues of Nucleosides: A New Synthesis of Antiviral Synguanol
作者:Zhimeng Wu、Shaoman Zhou、Jiri Zemlicka
DOI:10.1080/15257770902831060
日期:2009.4.28
Hydrolysis of compounds 11 and 13 in 80% acetic acid afforded (Z)-9-[2-(carbethoxycyclopropylidene)methyl]guanine (14) and (Z)-7-[2-(carbethoxy- cyclopropylidene)methyl]guanine (15). Reduction of 14 furnished synguanol (1). Reaction of N4-acetylcytosine (7) with ester 2c led to (Z,E)-1-(2-carbethoxycyclopropropylidenemethyl)cytosine (8, Z/E ratio 6.1:1). Basicity of purine base, lower reactivity of alkylation
描述了抗病毒合成胍醇 ( 1 ) 的立体选择性合成。6-苄氧基-2-(二甲氨基亚甲基氨基)嘌呤( 10 )与(顺,反)-2-氯-2-(氯甲基)环丙烷-1-羧酸乙酯( 2c )在烷基化-消除条件下反应得到(Z )-6-苄氧基-2-甲酰氨基-9-[(2-carbethoxycyclopropylidene)methyl]嘌呤( 11 )但没有E,N 9 -异构体。还获得了少量的(Z)-6-苄氧基-2-甲酰氨基-7-[(2-羧甲氧基-环亚丙基)甲基]嘌呤( 13 )。化合物11和13在 80% 乙酸中水解得到 (Z)-9-[2-(carbethoxycyclopropylidene)methyl] 鸟嘌呤 ( 14)和(Z)-7-[2-(碳乙氧基-环亚丙基)甲基]鸟嘌呤( 15 )。还原14提供的合成胍醇 ( 1 )。N 4 -乙酰胞嘧啶( 7 )与酯2c的反应产生(Z,E)-1-(2-羧甲氧基环亚丙基甲基)胞嘧啶(