Furoin Explained

Furoin or 1,2-di(furan-2-yl)-2-hydroxyethanone is an organic compound with formula C₁₀H₈O₄. It can be produced from furfural by a benzoin condensation reaction catalyzed by cyanide ions.^[1]

Reactions

Furoin synthesis from furfural is also catalyzed by vitamin B₁ (thiamine). In 1957, Ronald Breslow proposed that this reaction involves a relatively stable carbene form of thiamine.^{[2] [3]} 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 B₁:

This was the first evidence for the existence of persistent carbenes.

Uses

Furoin has been used as a plasticizer.^[1]

Notes and References

1. Denis Lorient (1999), New ingredients in food processing: biochemistry and agriculture. Woodhead Publishing 366 pages
2. Mechanism of Thiamine Action: Participation of a Thiazolium Zwitterion . Ronald Breslow . Chemistry and Industry . 26 . 893 . 1957.
3. Rapid Deuterium Exchange in Thiazolium Salts . R. Breslow . . 79 . 7 . 1762–1763. 1957 . 10.1021/ja01564a064.