Asymmetric biomimetic oxidations of phenols: the mechanism of the diastereo- and enantioselective synthesis of dehydrodiconiferyl ferulate (DDF) and dehydrodiconiferyl alcohol (DDA)
Stereoselective bimolecular radical coupling of enantiopure phenylpropenoidic phenols are described, starting from enantiopure amidic derivatives of ferulic acid. The latter were prepared from ferulic acid by reaction with (S)-alanine or Oppolzercamphorsultam. The oxidation step was performed both enzymatically (HRP/H2O2) and chemically (Ag2O). The observed enantioselectivity in the oxidation step
描述了对映体纯的丙烯丙烯基酚的立体选择性双分子自由基偶联,其起始于阿魏酸的对映体纯的酰胺衍生物。后者由阿魏酸通过与(S)-丙氨酸或Oppolzer樟脑sultam反应制得。氧化步骤既可以通过酶促(HRP / H 2 O 2)进行,也可以通过化学方法(Ag 2 O)进行。在氧化步骤中观察到的对映选择性范围为65-84%,与在PM3浓度下对醌甲基化物中间体的构象分析相一致。