Stereocontrolled Synthesis of Functionalized <i>cis</i>-Cyclopentapyrazolidines by 1,3-Dipolar Cycloaddition Reactions of Azomethine Imines
作者:Joshua Gergely、Jeremy B. Morgan、Larry E. Overman
DOI:10.1021/jo061537j
日期:2006.11.1
The reaction of alkene-tethered α-ketocarboxylic acid derivatives with monosubstituted hydrazines allows highly substituted cis-cyclopentapyrazolidine ring systems 4 to be constructed rapidly. Successful cyclocondensations are realized under thermal reaction conditions; in some cases, protic or Lewis acids accelerate these reactions. α-Methoxy-α,β-unsaturated esters are suitable alkene components, as