选择性糖基化:通过完全立体选择性硝酮环加成,Tamao-Fleming氧化和选择性α-葡萄糖基化为关键步骤,实现了天然木麻黄的全合成(1)和木麻黄的6 - O -α-葡萄糖苷的首次全合成(2)。两种化合物的生物学分析证明它们分别对葡糖淀粉酶NtMGAM和海藻糖酶Tre37A具有强大的选择性抑制特性,这使它们成为这些酶的最强抑制剂。
选择性糖基化:通过完全立体选择性硝酮环加成,Tamao-Fleming氧化和选择性α-葡萄糖基化为关键步骤,实现了天然木麻黄的全合成(1)和木麻黄的6 - O -α-葡萄糖苷的首次全合成(2)。两种化合物的生物学分析证明它们分别对葡糖淀粉酶NtMGAM和海藻糖酶Tre37A具有强大的选择性抑制特性,这使它们成为这些酶的最强抑制剂。
transformation of the reaction products allowed the synthesis of four new tetrahydroxylated indolizidines. Their activity as glycosidase inhibitors was evaluated against a panel of commercially available glycosidases. The specificity of inhibitory activity against amyloglucosidase and α-mannosidases depends on the configuration at C-2 of the indolizidine moiety.
Total synthesis of (-)-uniflorine A (3) has been accomplished in nine steps and 11% overall yield from carbohydrate-based nitrone 5. The key steps of the synthetic strategy were a high regio- and complete stereoselective 1,3-dipolar cycloaddition of alkene 6 with nitrone 5, a Tamao-Fleming reaction for replacing the silicon substituent with a hydroxy group with retention of configuration, and a Mitsunobu reaction to establish the correct configuration of the target molecule at C-6.
Total Syntheses of Casuarine and Its 6-<i>O</i>-α-Glucoside: Complementary Inhibition towards Glycoside Hydrolases of the GH31 and GH37 Families
作者:Francesca Cardona、Camilla Parmeggiani、Enrico Faggi、Claudia Bonaccini、Paola Gratteri、Lyann Sim、Tracey M. Gloster、Shirley Roberts、Gideon J. Davies、David R. Rose、Andrea Goti
DOI:10.1002/chem.200801578
日期:2009.2.2
Selective glucosylation: Total synthesis of naturally occurring casuarine (1) and the first total synthesis of casuarine 6‐O‐α‐glucoside (2) were achieved through complete stereoselective nitrone cycloaddition, Tamao–Fleming oxidation and selective α‐glucosylation as key steps. Biological assays of the two compounds proved their strong and selective inhibitory properties towards glucoamylase NtMGAM and
选择性糖基化:通过完全立体选择性硝酮环加成,Tamao-Fleming氧化和选择性α-葡萄糖基化为关键步骤,实现了天然木麻黄的全合成(1)和木麻黄的6 - O -α-葡萄糖苷的首次全合成(2)。两种化合物的生物学分析证明它们分别对葡糖淀粉酶NtMGAM和海藻糖酶Tre37A具有强大的选择性抑制特性,这使它们成为这些酶的最强抑制剂。