Lithiation and subsequent reaction with CO 2 was applied to calixarenes with different, equal or mixed, ether functions at the lower-rim site as well as tert-butylated or non-tert-butylated upper-rim positions. Whereas this reaction fails for symmetric calixarene ethers with alkoxy residues greater than methoxy, the carboxylation of mixed methoxy-propoxy calixarene ethers is possible. In connection with this, several new monobridge-substituted calixarenes were characterized with respect to their conformational behaviour in solution and the X-ray crystal structure of one key intermediate is taken into consideration. © 2011 Fischer et al; licensee Beilstein-Institut.
Fischer, C., Seichter, W., & Weber, E. (2011). Structural conditions required for the bridge lithiation and substitution of a basic calixarene. Beilstein Journal of Organic Chemistry, 7, 1602–1608. https://doi.org/10.3762/bjoc.7.188