Concerted Conjugate Addition of Nucleophiles to Alkenoates. 2. Synthesis of 2‘,3‘-Dideoxy-2‘-β-fluoro-3‘-(<i>N</i>-hydroxy-<i>N</i>- methylamino)-<scp>d</scp>-arabinofuranosyl Nucleosides
作者:Shifeng Pan、Jianwu Wang、Kang Zhao
DOI:10.1021/jo9815507
日期:1999.1.1
Conjugate Addition of Hydroxylamines to 4-Substituted Butenolides
4-Substituted-butenolides treated with free hydroxylamine at pH=5 undergo conjugate addition - rearrangement to afford isoxazolidin-5-ones. This is in contrast to N-substituted hydroxylamines which under the same conditions produce Michael adducts only. In the presence of base, butenolides undergo racemization via flat tautomeric forms.