Monday, October 21, 2013

Two chiral centers

Tartaric acid is a natural compound that is found in bananas, wine and grapes. It is usually used as a food additive and gives a sour taste to some candies, stabilizes egg whites and in baking powder is an active ingredient. I found it interesting too that in wine, tartaric acid causes wine diamonds to form on wine corks which are small crystals of potassium bitartrate. In addition to these uses, tartaric acid is used medically as a laxative and induces vomiting and works as an antioxidant stopping the formation of free radicals in the body. Despite the benefits of this acid, large amounts of it can be very harmful. If too much is ingested, it becomes a toxin and can lead to paralysis and even death however the amount of acid needed for this severe reaction to occur is great.
The chemical formula for tartaric acid is C4H6O6 and has two chiral centers. One on carbon 2 and the other on carbon 3. When assigning priorities to find the correct stereochemistry , going from highest to lowest one travels in the clockwise direction; but because the lowest priority is in the horizontal position, both chiral centers are S.


  1. This is a great blog. I never knew that bananas had an acid. What is more interesting is that Tartaric acid's enantiomer can be made artificially

  2. Your blog inspired me to do some research on the discovery of tartaric acid since it's uses are so widespread. Apparently it was discovered in 1970 by a guy named Carl Wilhelm Scheele, and, get this: the man never had any training in science and barely had any formal education. His job as an apprentice pharmacist coupled with his curiosity is essentially what drove him to conduct various experiments which eventually led him to discover tartaric acid and... oxygen! He named it "fire air" and usually the credit for its discovery goes to Joseph Priestley because he was able to publish his works on it first.