Reactions of N-cinnamoylaziridines by generation of aziridino ketyls from homolytic cleavage of Michael adducts
Abstract
High yields of the pyrrolidinones 2a, b are obtained from N-cinnamoylaziridines 1a, b and the carbanion ‘anthracene hydride’(anion of dihydroanthracene). Aziridino ketyls 3a, b are intermediates that probably arise by way of base-initiated homolytic fragmentation of an intermediate adduct. From reactions with xanthenyl anion X– it can be deduced that Michael addition is the first step, perhaps in the absence of steric hindrance (1a) accompanied by carbonyl addition. Reversibility of the addition with X– allows the irreversible nucleophilic ring-opening of 1a by X– to dominate in long term runs where the ultimate product is the spiro piperidinone 14. The trityl anion Tr– and 1a form a Michael adduct 26 that slowly homolyses to 3a giving finally the para substituted triphenylmethanes 22 and 23 which probably result from an SRN1 chain reaction.