7-Oxanorbornane and Norbornane Mimics of a Distortedβ-D-Mannopyranoside: Synthesis and Evaluation asβ-Mannosidase Inhibitors
作者:Stephan Buser、Andrea Vasella
DOI:10.1002/hlca.200590255
日期:2005.12
β-mannosidase was hardly inhibited by 3, 4, 42, 45, and 46. Only the amino triol 5 proved a stronger inhibitor. The inhibition by 5 depends on the pH value (at pH 3.5: Ki = 1900 μM; at pH 4.5: Ki = 340 μm; at pH 5.5: Ki = 110 μm). The results illustrate the strong dependence of the inhibition by bicyclic mimics upon the precise geometry and orientation of the amino group as determined by the scaffold. It
外消旋7- oxanorbornanyl和降冰片烷基氨基醇3,4,42,45,和46被合成并作为蜗牛测试β甘露糖苷酶抑制剂。氨基四醇3由已知的丙烯酸磺酰基酯9和呋喃10获得。酯化作用使11发生了对7-氧杂降冰片烯的分子内Diels-Alder反应12。将12还原为13,进行磺酰化,异亚丙基化和顺式-二羟基化反应,得到16。第二次异丙基亚丙基化为17然后再进行脱苄基反应和Mitsunobu-Gabriel反应,得到19个通过20至3脱保护的保护基。Diels-Alder将糠酸乙酸酯和马来酸酐环加成21,然后将酸酐进行醇化,顺式-二羟基化,异丙基化和Barton脱羧,得到酯25。脱乙酰基化为26,Mitsunobu-Gabriel反应导致27转化为N- Boc类似物29,还原为醇30,并取消保护到4。1-氨基降冰片烷5获自Thiele 's Acid 31。通过二酯32的热解,所得酸酐33的甲