6-(4-Hydroxy-3-methylbut-trans-2-enylamino)purine
(zeatin), a cytokinin isolated from Zea mays, has been synthesized by a new route. β- Methylcrotononitrile was brominated with N-bromosuccinimide
yielding γ- bromo-β-methylcrotononitrile,
from which trans-γ-acetoxy-β- methylcrotononitrile
was prepared. The alcohol derived from this acetate was converted into
trans-β-methyl-γ-(tetrahydropyran-2- yloxy)crotononitrile. Reduction and acid hydrolysis gave
4-amino-2- methylbut-trans-2-en-1-ol which was made
to react with 6-chloropurine to yield zeatin. ��� Several γ-alkoxy-β-methylcrotononitriles were prepared and reduced by
aluminium chloride-lithium aluminium hydride to the corresponding unsaturated
amines. Saturated nitrile formation also occurred in these reductions. The
amines prepared were condensed with 6-chloropurine to yield a series of O-alkylzeatins.
A number of other zeatin analogues were also synthesized. Two
6-methoxyalkylamino-purines were cleaved by sodium borohydride in the presence
of iodine to 6-hydroxy- alkylaminopurines.
6-(4-羟基-3-甲基丁-反式-2-烯氨基)嘌呤
(一种从玉米中分离出来的细胞分裂素--玉米素(zeatin)是通过一种新方法合成的。β-甲基巴豆腈与 N-溴代丁二酰亚胺进行溴化反应
生成γ-溴-β-甲基巴豆腈、
由此制备出反式-γ-乙酰氧基-β-甲基巴豆腈。
制得。由这种乙酸酯衍生的醇被转化为
反式-β-甲基-γ-(四氢吡喃-2-氧基)巴豆腈。还原和酸水解得到
4-amino-2- methylbut-trans-2-en-1-ol 与 6-氯嘌呤发生反应。
与 6-氯嘌呤反应生成玉米素。制备出了几种γ-烷氧基-β-甲基巴豆硝酸酯,并用氯化铝-硫酸铝还原了它们。
氯化铝-氢化铝锂还原成相应的不饱和胺。
胺。在这些还原反应中也会形成饱和腈。制备的胺
胺与 6-氯嘌呤缩合,生成一系列 O-烷基玉米素。
此外,还合成了其他一些玉米素类似物。两种
在碘的存在下,硼氢化钠将两个 6-甲氧基烷基氨基嘌呤裂解为 6-羟基嘌呤。
在碘存在下,两种 6-甲氧基烷基氨基嘌呤被硼氢化钠裂解为 6-羟基烷基氨基嘌呤。