The unusual formation of methyl α‐(5,6‐dimethoxycarbonyl‐2,3‐dimethoxyazepin‐7‐ylidene)‐α‐[5‐methoxycarbonyl‐2,3‐dimethoxypyrid‐6‐yl)acetate during the pyrolysis of “Azido‐meta‐hemipinate”: First example of a reaction involving a concomitant ring expansion and ring extrusion | Publicación