Diastereoselective [2+2]-Cycloaddition Reactions of Unsymmetrical Cyclic Ketenes with Imines: Synthesis of Modified Prolines and Theoretical Study of the Reaction Mechanism
作者:Alberto Macías、Eduardo Alonso、Carlos del Pozo、Alessandro Venturini、Javier González
DOI:10.1021/jo040163w
日期:2004.10.1
The synthesis of enantiomerically pure modified proline derivatives was achieved by using spiro β-lactams as starting material that were prepared in turn by the [2+2]-cycloaddition of unsymmetrical cyclic ketenes with optically active imines. A theoretical study of the [2+2]-cycloaddition reaction, using density-functional methods, gave insights on the origin of the observed stereoselectivity of the