Two-Step Metal-Mediated Transformation of Isoxazolidine-5-spirocyclopropanes into Pyridone Derivatives
作者:Julia Revuelta、Stefano Cicchi、Alberto Brandi
DOI:10.1021/jo050640q
日期:2005.7.1
The two-step metal-catalyzed overall transformation of isoxazolidine-5-spirocyclopropanes into the corresponding dihydro- and tetrahydropyridones is described. The first step is the chemoselective reduction of the N-O bond of the isoxazolidine ring preserving the fragile cyclopropanol moiety while the second transformation is the Pd(II) or Pd(O) conversion of the beta-aminocyclopropanol derivatives into the final compounds. The scope and limitations of this strategy are described.
Samarium(II) iodide reduction of isoxazolidines
作者:Julia Revuelta、Stefano Cicchi、Alberto Brandi
DOI:10.1016/j.tetlet.2004.09.050
日期:2004.11
SmI2 was used as reducing agent for the N-O bond cleavage in isoxazolidines. The procedure revealed is general and particularly useful for the transformation of 5-spirocyclopropane isoxazolidines to the corresponding beta-aminocyclopropanols, a troublesome transformation with other known reagents. (C) 2004 Elsevier Ltd. All rights reserved.