This work describes the first examples of diastereoselective intramolecular cyclopropanations of a de novo class of push–pull carbenes derived from DMDO-epoxidations of chiral ynamides. This reaction sequence essentially constitutes a tandem epoxidation–cyclopropanation that effectively gives rise to a series of structurally unique amido-cyclopropanes. A plausible mechanistic model is proposed revealing insights into this novel cyclopropanation process.