Conversion of methyl 9(10)‐formylstearate to carboxymethylstearate

Abstract

Methyl 9(10)-formylstearate was converted to methyl 9(10)-carboxymethylstearate. The reactions to prepare the intermediates methyl 9(10)-hydroxymethyl-, 9(10)-acetoxymethyl-, 9(1 0)-methylene-, and 9(10)-formylmethylstearate are described. Methyl 9(10)-hydroxymethylstearate readily loses methanol and forms a trimeric polymer. The acetate of the primary alcohol when pyrolyzed gives 59% yield of methyl 9(10)-methylenestearate. Hydroformylation of the methylene compound followed by permanganate oxidation gave methyl carboxymethylstearate. Evidence is presented to show that pyrolysis of the acetate ester and hydroformylation of the pyrolysis product produce, respectively, only the methylene and formylmcthylstearates. Rates of esterification-transesterification of methyl 9(10)-carboxymethylstearateshow that the carboxymethyl group is 2-3 times as active as the carboxyl group in methyl 9(10)-carboxystearate and that the terminal carboxyl group is about 10 times more active towards esterification than the branched carboxymethyl group.