Methyl triisopropylacetate

Heating of methyl esters (e.g., 216) with 10 mol equiv. of DBU in o-xylene resulted in O-methyl cleavage to give the corresponding acids (e.g., 217) in exellent yields (73JOC1223). This method could also be applied to hindered esters (e.g., methyl mesitoate or methyl triisopropylacetate) and esters containing hydrolytically sensitive functional groups. 

Methyl triisopropylacetate heated 4 hrs. at 100 with K-ferf-butoxide in dimethyl sulfoxide triisopropylacetic acid. Y almost 100%. F. e. s. F. G. Ghang and N. F. Wood, Tetrah. Let. 196, 2969. 

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