Amino acid derived intramolecular 1,3-dipolar cycloadditions that form bridged medium ring systems with diastereoselective control
作者:Yanbin Liu、Amy Maden、William V Murray
DOI:10.1016/s0040-4020(02)00242-9
日期:2002.4
Intramolecular nitrone cycloadditions using amino acid precursors, generate aminohydroxyazepine and amino hydroxypiperidine templates. The cycloaddition reactions yield either a [4.3.0] fused system or in most cases a [4.2.1] bridged system. The [4.2.1] bridged system allows for the stereospecific preparation of 3-amino-5-hydroxyazepines while the [4.3.0] system allows for the preparation of 3-amino-5-hydroxymethyl
Modulating chitin synthesis in marine algae with iminosugars obtained by SmI<sub>2</sub> and FeCl<sub>3</sub>-mediated diastereoselective carbonyl ene reaction
were tested. For samarium diiodide we observed a superior stereoselectivity in comparison to iron(III) chloride and methylaluminium dichloride. To increase water solubility for testing and measurement of enzyme activity, the cyclization products were further functionalized. We established a novel biological chitin synthesistest system which allows quantitative investigation of chitin synthesis in the