title: Ketopantoic acid
text: # Ketopantoic acid
  
  Ketopantoic acid is the organic compound with the formula $HOCH_2(CH_3)_2CC(O)CO_2H.$ At physiological conditions, ketopantoic acid exists as its conjugate base, ketopantoate $(HOCH_2(CH_3)_2CC(O)CO_2^−).$
  
  ## Biosynthetic context
  
  Its biosynthesis proceeds from ketoisovalerate by hydroxymethylation:
  
      $(CH_3)_2CHC(O)CO_2^−$ + $CH_2O$ → $HOCH_2(CH_3)_2CC(O)CO_2^−$
  
  This conversion is catalyzed by ketopantoate hydroxymethyltransferase, which gives ketopantoate.
  
  Ketopantoate is substrate for 2-dehydropantoate 2-reductase, which produces pantoate, a precursor to pantothenic acid, a common prosthetic group.
  
  