Preparation of 4-ethoxy-2,3-dihydroxy-4-oxobutanoic acid
20 g of finely powdered tartaric acid and 30 g of absolute alcohol are heated for 6 hours at 70° C on a water bath under reflux. An equal volume of water and then an excess of powdered barium carbonate are added, and the liquid filtered from barium tartrate and excess of barium carbonate. The filtrate is evaporated to crystallisation on a water bath, cooled, and the crystals of barium salt of 4-ethoxy-2,3-dihydroxy-4-oxobutanoic acid which separate filtered off and dried on a porous plate. They are weighed and treated with the theoretical amount of 2N sulphuric acid to precipitate the barium present, barium sulphate is filtered off, and the filtrate evaporated to crystallisation point. The crystals which separate are recrystallised from a little water. Yield 70%, colourless crystals; somewhat soluble in water, m.p. 90° C.
Systematic organic chemistry, by W. M. Cumming, 254-255, 1937.
4-ethoxy-2,3-dihydroxy-4-oxobutanoic acid, Butanedioic acid, 2,3-dihydroxy- (2R,3R)-, 1-ethyl ester, Butanedioic acid, 2,3-dihydroxy- (2R,3R)-, monoethyl ester, Ethyl tartrate, acid, Ethyl hydrogen (R-(R*,R*))-tartrate, 608-89-9, monoethyl tartrate, AC1L2ST3, SCHEMBL1038609, CTK8D4408, AC1Q6423, EINECS 210-171-5, AR-1G2126, Tartaric acid hydrogen 1-ethyl ester, CA010763, OR045024, 551-75-7
CID102448, 97451-46-2, 91469-75-9