Intermediates for incorporation of tetrahydroxypipecolic acid analogues of α- and β-d-mannopyranose into combinatorial libraries: unexpected nanomolar-range hexosaminidase inhibitors. Synthesis of α- and β-homomannojirimycin
作者:John P Shilvock、Robert J Nash、Janet D Lloyd、Ana L Winters、Naoki Asano、George W.J Fleet
DOI:10.1016/s0957-4166(98)00365-6
日期:1998.10
are suitable intermediates for the incorporation of tetrahydroxypipecolic acid derivatives into combinatorial libraries containing α- and β-C-glycosyl analogues of aza-d-mannopyranose, respectively. Methylamides derived from 7 and 9 are shown to be specific and potent inhibitors of two β-N-acetylglucosaminidases but have no effect on an α-N-acetylgalactosaminidase. The synthesis of α-14 and β-17 manno-pipecolic
均一糖类作为一类天然产物的区别在于它们中的大多数是在分离之前就已经合成的。α - 1和β-高甘露糖霉素2的合成依赖于[2.2.2]双环亚氨基内酯(6)的立体选择性和化学选择性氰基硼氢化钠还原,得到单个[2.2.2]双环氨基内酯(7)。在碱性条件下7的甲醇分解反应伴随着第一个形成的α-氨基酯(8)的有效差向异构化作用,而其中2,6-取代基是赤道的更稳定的β-氨基酯(9)。双方7和9适当的中间体是用于将四羟基哌酸衍生物掺入分别含有氮杂-d-甘露聚糖的α-和β-C-糖基类似物的组合文库中的中间体。已显示衍生自7和9的甲基酰胺是两种β-N-乙酰氨基葡萄糖苷酶的特异强效抑制剂,但对α-N-乙酰半乳糖苷酶没有影响。还报道了α- 14和β- 17甘露糖酚酸的合成。