The First and Second <i>Cinchona</i> Rearrangement. Two Fundamental Transformations of Alkaloid Chemistry
作者:M. Heiko Franz、Stefanie Röper、Rudolf Wartchow、H. M. R. Hoffmann
DOI:10.1021/jo030363s
日期:2004.4.1
Stereochemistry, products, and driving forces of the “first and second Cinchona rearrangement” have been investigated and a unified theory is presented. The first cage expansion affords [3.2.2]azabicyclic α-amino ether and is formulated via a configurationally stable bridgehead iminium ion and quasiequatorial nucleophilic attack. The second cage expansion affords β-functionalized [3.2.2]azabicycles