First carbamoyloxa-bridged cyclophane: synthesis and crystal structures of two isolable conformers

The coupling of m-xylylenediisocyanate with m-xylylenediol through a modified polyurethane synthesis scheme yields the first carbamoyloxa-bridged cyclophane, which contains two conformers. Crystallization of cyclophane from dichloromethane/chloroform yields anti-(E, E) structured conformer as single crystals. Recrystallization of the conformer from methanol/ethanol solution yields the anti-(z,z) structured conformer. X-ray crystallography confirms the structures.