New approach to the synthesis of dibenzodiazacrown ethers by ring transformation of dibenzocrown ether

Opening of the macrocycle of 4′,4″(5″)-dinitrodibenzo-18-crown-6 ethers under the action of MeNH2 or MeONa to give podands was studied. Structure of the aza podands was confirmed by X-ray diffraction. A new approach to the synthesis of previously unknown dinitrodibenzodiazacrown ethers based on one-step ring transformation of the cis isomer of dinitrodibenzo-18-crown-6 ether on treatment with aliphatic diamines was proposed.