4‐Acyl‐2,3,4,5‐tetrahydro‐2‐methyl‐2,5‐methanobenz‐1,4‐oxazepine, Derivatives of a New Heterocycle

Two rotamers that are stable in the solid state can be isolated separately for the heterocycle 1. Variation of the crystallization method provides the two modifications that differ in the orientation of the carbonyl group on nitrogen: the CO group points either towards the benzene ring (depicted right) or away from it.