Total Synthesis and Structural Revision of the Presumed Aeruginosins 205A and B
作者:Stephen Hanessian、Xiaotian Wang、Karolina Ersmark、Juan R. Del Valle、Ellen Klegraf
DOI:10.1021/ol901702k
日期:2009.9.17
A stereoselective synthesis of enantiopure aeruginosin 205B aglycon confirms the presence of a (3R,2S)-3-chloroleucine amide residue and a (6R)-hydroxy (4aR,7aS)-octahydroindole-(2S)-2-carboxamide (Choi) subunit instead of a 6-chloro-substituted core (Ccoi). Enzyme inhibitory tests against thrombin revealed an IC50 of 0.31 μM. The totalsynthesis of the presumed aeruginosin 205B shows that the α-d-xylopyranosyl
The Direct Synthesis of Methyl 2,4-Di-<i>O</i>-benzyl-α-D-xylopyranoside by the Regiospecific Benzylation of Methyl α-D-Xylopyranoside
作者:Naohiko Morishima、Shinkiti Koto、Chiharu Kusuhara、Shonosuke Zen
DOI:10.1246/bcsj.55.631
日期:1982.2
The regiospecific benzylation of methyl α-D-xylopyranoside with benzyl chloride and sodium hydride produces methyl 2,4-di-O-benzyl-α-D-xylopyranoside in a 70% yield, together with the by-products, methyl 2,3- and 3,4-di-O-benzyl-α-D-xylopyranosides. The structure of the 2,4-di-O-benzyl derivative was confirmed through the alternative synthesis of the 2,3- and 3,4-di-O-benzyl derivatives via the O-isopropylidene