Novel Asymmetric Approach to Proline-Derived Spiro-β-lactams
作者:Alisher B. Khasanov、Michele M. Ramirez-Weinhouse、Thomas R. Webb、Mohan Thiruvazhi
DOI:10.1021/jo049430o
日期:2004.8.1
We describe a novel asymmetric approach using Staudinger chemistry to proline-derived spiro-β-lactams. A chiral group at C-4 of the acid chloride of proline directs the stereoselectivity of Staudinger chemistry and later is sacrificed to obtain optically active 5.4-spiro-β-lactams. The scope, limitations, and mechanistic rationale for the observed results of Staudinger Chemistry of the acid chloride
Enantiomerically Pure Polyheterocyclic Spiro-β-lactams from <i>trans</i>-4-Hydroxy-<scp>l</scp>-proline
作者:Giuseppe Cremonesi、Piero Dalla Croce、Francesco Fontana、Concetta La Rosa
DOI:10.1021/jo100061s
日期:2010.3.19
The "Staudinger ketene-imine reaction" between ketenes generated from natural O,N-protected trans-4-hydroxy-L-prolines and the N-benzyl-N-benzylideneamine led to mixtures of diastereoisomeric, enantiomerically pure pyrrolidine-derived spiro-beta-lactams with a relative cis configuration. These were transformed into the corresponding pyrroline-spiro-beta-lactams by means of treatment with a base and the new C = C double bond Was Submitted to a number of different reactions in order to evaluate its reactivity and obtain new polyheterocyclic enantiomerically pure spiro-beta-lactams.