A comparison of 3, 4, 6a, 7, 10, 10a‐hexahydro‐7, 10‐epoxypyrimido[2, 1‐a]isoindol‐6(2H)‐one and 2‐(2‐aminoethyl)‐3a, 4, 7, 7a‐tetrahydro‐1H‐4, 7‐epoxyisoindole‐1, 3(2H)‐dione: structural and reactivity differences of two homologous tricyclic imides. (9th May 2013)