Acylation and Aroylation Routes

Treatment of calixarenes with acetyl chloride or benzoyl chloride in the presence of AICI3 at or below room temperature generally results in esterification to give 176. To achieve p-substitution the calixarene ethers have been used to give 177 (Y = alkyl n = 4, 6). The esters 176, however, can be converted to 177 (Y = H) by the Fries rearrangement, carried out with AICI3 at higher 

Arimura, T. Shinkai, S. Matsuda, T. Hirata, Y. Satoh, H. Manabe, O. Bull. Chem. Soc. Jpn. 

Still another route for selective formylation makes use of the tricarbonyl-chromium complexes of calix[4]arenes. Reaction of the tetrapropyl ether of 4 with Cr(CO)3 produces a complex in which a Cr(CO)3 moiety is associated with a single aromatic residue of the calixarene. Treatment of the complex with BuLi and then D2O, Mel, or DMF followed by decomplexation with I2 yields mono-substituted calix[4]arenes carrying D at a p- or m-position. Me at a p-position, and CHO at a p-position, respectively.  

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