The syntheses of the polyhydroxylated piperidines deoxygalactonojirimycin 2, homogalactonojirimycins 7 and 9, and other 2,6-iminoheptitol derivatives, including an analogue of L-altropyranose, are reported. 5-Azidoaldono-1,4-lactones undergo chain extension to afford azido lactols by the addition of a hydroxymethyllithium species 18, generated by transmetallation of a protected stannylmethanol derivative 17. Hydrogenation results in azide reduction with subsequent intramolecular reductive amination to give piperidine ring systems. The deprotected iminogalactopyranose analogues are potent and selective α-galactosidase inhibitors. Observations on the structural features determining selectivity of inhibition of α-galactosidases over naringinase (L-rhamnosidase) are also reported.
报告了多羟基
哌啶脱氧半
乳糖苷尻霉素 2、均半
乳糖苷尻霉素 7 和 9 以及其他 2,6-亚
氨基
庚醇衍
生物(包括一种 L-altropyranose类似物)的合成。5-Azidoaldono-1,4-lactones 经历了链延伸,通过添加羟
甲基锂 18 得到
叠氮内酯,羟
甲基锂是由受保护的链烷
甲醇衍
生物 17 反
金属化生成的。氢化反应导致
叠氮还原,随后进行分子内还原胺化反应,得到
哌啶环系统。去保护的亚
氨基半乳
糖类似物是强效的选择性δ-半
乳糖苷酶
抑制剂。报告还观察了决定δ-半
乳糖苷酶抑制
柚皮苷酶(
L-鼠李糖酶)选择性的结构特征。