Acyl compounds spectroscopic properties

Calixarenes, in which only some of the hydroxy functions are O-alkylated or O-acylated, are important derivatives by themselves and interesting intermediates for the construction of more sophisticated compounds. Selected H NMR spectroscopic properties of partial ethers of 2a have been summarized in Table 4. The distinction of regioiso-mers and conformational isomers becomes more and more complicated for the higher macrocycles. 

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