Acid-catalyzed acetylation of N-methallyl lactam and imide derivatives

Abstract

The reactions of N-methallyl derivatives of cyclic amides and imides with acetic and propionic anhydride have been studied in the presence of perchloric acid. The reaction products have been found to be pyrylium and oxazolinium salts. The relationship between the reaction pathway and the structure of the imide or amide starting material has also been determined. Pyrylium salts have been converted to their corresponding pyridine bases.