Aromatic Ring Oxidation to Spirodienones

Strong oxidizing agents convert the phenolic rings of calixarenes to quinones, as discussed above, but milder oxidizing agents produce compounds in which one 

The calix-spirodienones undergo a variety of reactions and are useful intermediates for effecting alterations at the lower rim. Treatment with NH2NH2 at room temperature yields the bridged compound 242while under the more 

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