The 1-Aza-Cope Rearrangement

Article abstract of DOI:10.1021/jo00240a006

The 1-aza-Cope rearrangement of azavinylcyclohexene derivatives were investigated.It was observed that an N-acyl substituent on the 1-aza 1,5-diene provides a sufficient driving force for this normally contrathermodynamic process.Although simple derivatives have high activation energies proceeding in relative low overall yield, a methoxy substituent at C-4 of the aza diene as well as its incorporation into strained bicyclic ring systems facilitates the 1-aza-Cope rearrangement.Because the aza diene precursors are readily available by using the Diels-Alder reaction with acrolein derivatives, this process has synthetic potential for the preparation of nitrogen heterocycles.This scheme is illustrated with the preparation of a hydrolulolidine providing a formal total synthesis of (+/-)-aspidospermine.