THE SYNTHESIS OF ANTHRACENE CROWN-ETHERS DERIVED FROM BENZO-CROWN ETHERS

The sulfuric acid-promoted reaction of benzo-15-crown-5 (3) and benzo- 18-crown-6 (6) with aliphatic aldehydes, leading to the formation of a nthracene crown ethers, was studied. A substantial substituent effect on the reaction course was found. For the isobutyl group the highest y ield was obtained, while for longer and shorter alkyl groups the yield dropped down Reaction of acetaldehyde and benzo-15-crown-5 leads to f ormation of compound 4 in 35% yield Application of cyclohexanone as a carbonyl reagent caused formation of till now unknown 4,5-disubstitute d crown ether 8. (C) 1998 Elsevier Science Ltd. All rights reserved.