Cyclopropanation vs. single-carbon insertion of pyrrole-2,3-diones with sulfonium ylides: synthesis of functionalized 2-azabicyclo[3.1.0]hexanes and pyridine-2,3-diones

The method for the diastereoselective synthesis of pyrrole-annulated donor-acceptor cyclopropanes from pyrrole-2,3-diones and stabilized sulfonium ylides has been developed. Ring opening of these annulated cyclopropanes (spontaneous or Lewis acid/thermal mediated)...