What is the difference between D-(-)-Tartaric Acid and D(+)-tartaric acid?

D-(-)-Tartaric Acid and D(+)-tartaric acid are both D-enantiomers of tartaric acid. They are similar but come from different sources, so they are easily confused. This confusion arises because tartaric acid is related to the reference compound D(+)-glyceraldehyde in two different ways, leading to opposite conclusions: (+)-Tartaric acid is related to D(+)-glyceraldehyde through a series of reactions : (+)-Tartaric acid → (+)-malic acid → (+)-isoserine → (−)-glyceric acid → (+)-glyceraldehyde: hence D(+)-tartaric acid. (−)-Tartaric acid is obtained by oxidation of D-threose, and its structure is related to D(+)-glyceraldehyde: hence D(−)-tartaric acid.

References:

[1] BUCHANAN C. Configurational Notation of the Tartaric Acids[J]. Nature, 1951, 167 4252: 689-690. DOI:10.1038/167689a0.

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