New methods for the preparation of inherently chiral calixarenes have been developed. The molecular asymmetry in these calixarenes is created by an asymmetrical disposition of naphthalene rings on the upper rim. In compound 1, monoformylcalixarene 5 was transformed into naphthalene-containing calixarene by ring closure. In compound 2, p-chloromethyl groups are intramolecularly cross-linked with 3-hydroxymethyl-2-naphthol. This 'stapling reaction' results in a syn isomer 2a and an anti isomer 2b, the latter being classified into an inherently chiral calixarene. Racemic anti 2 could be 'perfectly' optically resolved by an HPLC method with a chiral-packed column. The chiral products were thoroughly characterized by various spectroscopic methods. These results indicate that the naphthalene skeleton is very useful for creating molecular asymmetry in calixarenes.
|Number of pages||6|
|Journal||Journal of the Chemical Society - Perkin Transactions 1|
|Publication status||Published - Aug 21 1996|
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