In organic chemistry, the benzoin addition is an addition reaction involving two aldehydes (−CH=O). The reaction generally occurs between aromatic aldehydes or glyoxals (OCH=CHO),[1][2] and results in formation of an acyloin (−C(O)CH(OH)−). In the classic example, benzaldehyde is converted to benzoin (PhCH(OH)C(O)Ph).[3]
The benzoin condensation was first reported in 1832 by Justus von Liebig and Friedrich Wöhler during their research on bitter almond oil.[4] The catalytic version of the reaction involving cyanide was developed by Nikolay Zinin in the late 1830s.[5][6]