Modified Crown Ether Catalysts. 2. Synthesis of Alkanoyl-, Aroyl-, α-Hydroxyalkyl- and Alkylbenzo and Alkylcyclohexano Crown Ethers

Article abstract of DOI:10.1021/jo01311a033

Improved procedures for the synthesis and purification of alkanoyl- and aroylbenzo crown ethers are reported.Several new alkanoyl- and α-hydroxyalkylbenzo crown ethers were prepared.Alkylbenzo crown ethers were prepared in high yield by the Raney nickel catalyzed hydrogen-transfer reductions of the corresponding acyl- or hydroxyalkylbenzo crown ether compounds.The reduction of the tosylhydrazones of acylbenzo crown ethers with sodium borohydride in acetic acid also yielded the corresponding alkyl derivate.Attempted reduction of the acyl- and α-hydroxyalkylbenzo crown ethers by catalytic hydrogenation over palladium catalysts was unsuccessful apparently due to strong binding of the crown ethers to the catalyst.Alkylcyclohexano crown ethers were prepared by catalytic hydrogenation of the aromatic rings of the corresponding alkylbenzo crown ethers.