Preparation of polyether polycarboxylic acids containing quaternary carbon atoms in the backbone

Abstract

The addition of chloromethyl ethers (4a–c), (10a), and (11a) to 1-methoxy-2-methylprop-1-ene (5) is catalysed by mercury(II) chloride. Hydrolysis of the resulting chloro-ethers [e.g. (6a)] gives 3-alkoxy-2,2-dialkylpropanals [e.g. (7a)] which can be oxidised to the corresponding carboxylic acids [e.g. (8a)] with hydrogen peroxide in the presence of selenium dioxide as catalyst. Poly(alkoxyacetic) acids have been obtained by reaction of alkoxides with NN-dialkylchloroacetamides followed by hydrolysis. Thus the acids (12a–c) have been obtained from 2,2-dimethylpropane-1,3-diol, 2-hydroxymethyl-2-methylpropane-1,3-diol, and pentaerythritol, respectively.