Benzyl Alcohol → Malic Acid

Participants

Reaction Steps

In an example of the process wherein the cyclic anhydride is formed with a diimide, D-malic acid is dissolved in tetrahydrofuran and 1.1 molar equivalents of dicyclohexylcarbodiimide are added to the solution. The reaction mixture is stirred for about an hour and is then filtered to remove the precipitate of dicyclohexylurea. An excess (ca. 1.5 to 2.0 equiv.) of benzyl alcohol is added to the filtrate containing the malic acid cyclic anhydride and the solution is stirred for about 6 to about 12 hours. The reaction mixture is evaporated and the impure monobenzyl malate is dissolved in a water immiscible solvent such as ethyl acetate. The product is extracted with a base such as aqueous sodium bicarbonate, and after acidification of the extract the ester is extracted with ethyl acetate or other suitable solvent. The extract is dried and evaporated to yield the monobenzyl ester of malic acid represented by the formula ##STR51##

Provenance & Evidence