Intermolecular dearomatising addition of organolithium compounds to N-benzoylamides of 2,2,6,6-tetramethylpiperidine

N-Benzoylamides of 2,2,6,6-tetramethylpiperidine are not ortholithiated by organolithium compounds but instead undergo nucleophilic addition of the organolithium compound to the aromatic ring in the manner of a conjugate addition. The resulting dearomatised enolates may be protonated or alkylated, and yield substituted cyclohexadienes in yields of up to 76%. Deprotection of the piperidine ring is possible under acidic conditions.