3 Oxopentanoic acid

3-Oxopentanoic acid, or beta-ketopentanoate, is a 5-carbon ketone body. It is made from odd carbon fatty acids in the liver and rapidly enters the brain.

As opposed to 4-carbon ketone bodies, beta-ketopentanoate is anaplerotic, meaning it can refill the pool of TCA cycle intermediates. The triglyceride triheptanoin is used clinically to produce beta-ketopentanoate.