A novel and stereo-controlled method for the preparation of functionalized macrolactams was developed. The process involves stereoselective enolether formation, followed by an azacyclic ring expansionvia an aza-Claisen rearrangement. Herewith, we describe a systematic investigation of an aza-Claisen rearrangement-induced ring expansion of azacycles prepared by appending E/Z-enol ethers to the medium-sized