Direct Synthesis of Benzophenanthridines and Benzophenanthridones via SRN1 Reactions

Article abstract of DOI:10.1021/jo00224a057

A straightforward and high-yield route to the 11,12-dihydrobenzophenanthridine (3) and 11,12-dihydrobenzophenanthridone (14) ring systems is based upon an S_RN1 reaction between 2-halobenzylamines 1 or 2-halobenzoic acids 11 and enolates derived from tetralones 2.The efficient dehydrogenation of 3 or 14 gives the benzophenthridines 4 or benzophenanthridones 15.Use of properly substituted reactants leads to nitidine, avicine, and fagaronine and to analogues of those natural products.