| Abstract
| - Treatment of calix[4]arene bis-O-carbamates 4a,b−6a,b with LDA in THF results in the regio-and stereoselective introduction of both axial and equatorial carboxamide groups at the methylenebridges via a homologous anionic ortho-Fries rearrangement to give 7−16. The stereochemicaloutcome of the rearrangement is dependent on the reaction conditions and the conformation of thestarting material. Stereochemical and structural proof has been secured by the X-ray crystalstructure of calix[4]arene 10 having only one equatorial carboxamide moiety. The use of this novelclass of methylene bridge-functionalized calix[4]arenes is illustrated by the formation of bis-γ-lactone 19, while the enhanced acidity of the remaining hydroxyl groups, owing to the presence ofaxial carboxamide groups at the methine bridges, followed from the easy propylation of bisrearranged calix[4]arene 7.
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