title: Furoin
text: # Furoin
  
  Furoin or 1,2-di(furan-2-yl)-2-hydroxyethanone is an organic compound with formula $C_{10}H_8O_4.$ It can be produced from furfural by a benzoin condensation reaction catalyzed by cyanide ions.
  
  ## Reactions
  
  Furoin synthesis from furfural is also catalyzed by vitamin $B_1$ (thiamine). In 1957, Ronald Breslow proposed that this reaction involves a relatively stable carbene form of thiamine. In the catalytic cycle shown below two molecules of furfural react to give furoin, via a thiazol-2-ylidene catalyst, resulting from loss of one proton at carbon 2 of the thiazolium cation of vitamin $B_1:$
  
  This was the first evidence for the existence of persistent carbenes.
  
  ## Uses
  
  Furoin has been used as a plasticizer.
  
  