O- and N-alkylation with "Meerwein's reagent": the unusual behaviour of two lactams.

Usually tertiary oxonium salts are excellent O-alkylating agents of lactams; in some cases indiscriminate O- and N-alkylations have been described. In this paper the particular behaviour towards Meerwein's reagent of two isomers with a lactamic structure is pointed out: in one case the usual O-alkylation occurs, in the other N-alkylation is the only reaction that takes place.