The reaction between a nitrile and an alkoxide base leads to the formation of a β-iminonitrile from which an α-cyanoketone is obtained by mild acid hydrolysis. This reaction is known as the Thorpe reaction when intermolecular, and the Thorpe-Ziegler reaction when intramolecular. It is to say that this reaction is a series of Claisen condensation.
The Thorpe-Ziegler reaction is especially useful in the formation of five- to eight membered rings and for rings with more than thirteen members, although it fails for nine- to twelve-membered rings.
・ Baron, H.; Remfry, F. G. P.; Thorpe, Y. F. J. Chem. Soc. 1904, 85, 1726.
・ Karl Ziegler et al. Ann. 1933, 504, 94.
・ Schaefer, J. P.; Bloomfield, J. J. Org. React. 1967, 15, 1.