作者:Kevin W. Glaeske、F. G. West
DOI:10.1021/ol9905349
日期:1999.7.1
Cyclic ammonium salts 2 were prepared by diastereoselective quaternization of nitrogen in the corresponding proline or threonine derivatives. Upon treatment with base, salts 2 underwent [1,2]- or [2,3]-shift to 3 with moderate to complete stereospecificity. The overall process entails chirality transfer from the original alpha carbon to the neighboring nitrogen and then back to the carbon.