Cryptate and Resin Catalyzed Esterifications

Crown complexed potassium acetate has recently been used to initiate the polymerization of acrylic acid [27]. 

Not only will crown ethers, quaternary ions, and amines catalyze the esterification reaction, but cryptates are also effective in this application. Potassium carboxylates react in good yield with a variety of alkyl halides in the presence of a catalytic amount of [2.2.2]-cryptafe to yield the corresponding esters [28]. The results are summarized in Table 6.9. 

The alkylation of carboxylates to yield esters has also been catalyzed by quaternary ammonium groups bound to a macroreticular resin. Amberlite IRA-904 was converted to the hydroxyl form and then treated with the acid to form ammonium carboxylate ion pairs. The alkylation was carried out by a batch process in such solvents as ether, hexane, or ethanol, as illustrated in equation 6.11 [29]. The results are summarized in Table 6.10. 

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