Synthetic Approach to<i>N</i>-Alkylated 2,5-Diamino-2,5-dideoxy-1,4;3,6- dianhydroalditols by Reductive Alkylation
作者:Gerrit Limberg、Joachim Thiem
DOI:10.1055/s-1994-25468
日期:——
N,N′-Dialkylated 2,5-diamnno-2,5-dideoxy-1,4;3, 6-dianhydroalditols, representing interesting basic catalysts for polyaddition reactions, are synthesized by different reductive alkylation procedures in satisfactory yields. D-Gluco- and L-ido-N, N′-dialkyl-2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroalditols 7-8, 10-15 are accessible by reaction of the corresponding diamines with carbonyl compounds and reduction of the intermediately formed imine. For the synthesis of D-manno-N,N′-dialkylated diamines, an alternative route via 1,4;3,6-dianhydro-D-threo-2,5-hexodiulose (18) is established, thus avoiding the six-step synthesis towards 1,4;3,6-dianhydro-D-mannitol (2). Reductive alkylation of diketone 18 yields stereospecifically only the alkylated diamine 21 with D-manno-configuration. In case of the monoketones only 1,4;3,6-dianhydro-L-sorbose (16) can be transformed stereospecifically to N-2-pentyl-5-amino-5-deoxy-1,4;3,6-dianhydro-D-sorbitol (19), whereas 1,4;3,6-dianhydro-D-fructose (17) yields a mixture of D-manno- and D-gluco-monoamines 20a and 20b by reductive alkylation with 2-pentylamine and sodium borohydride.
通过不同的还原烷基化程序合成了 N,N′-二烷基-2,5-二氨基-2,5-二脱氧-1,4;3,6-二脱氢-1,4;3,6-二羟基-2,5-二烷多酚,它们是用于加成反应的有趣的基本催化剂,产量令人满意。通过相应的二胺与羰基化合物反应并还原中间形成的亚胺,可以得到 D-葡糖基和 L-亚氨基-2,5-二氨基-2,5-二脱氧-1,4;3,6-二氢二羟醇 7-8、10-15。合成 D-甘露-N,N′-二烷基二胺的另一条途径是通过 1,4;3,6-二氢-D-苏-2,5-己二酮糖(18),从而避免了 1,4;3,6-二氢-D-甘露醇(2)的六步合成法。 二酮 18 的还原烷基化只产生具有 D-甘露构型的烷基化二胺 21。至于单酮,只有 1,4;3,6-二氢-L-山梨糖(16)可以立体定向地转化为 N-2-戊基-5-氨基-5-脱氧-1,4;3,6-二氢-D-山梨糖醇(19),而 1,4;3,6-二氢-D-果糖(17)则可以通过 2-戊胺和硼氢化钠还原烷基化反应生成 D-甘露和 D-葡萄糖单胺 20a 和 20b 的混合物。