Steric effects in high pressure Knoevenagel reactions

The pressure effect in Knoevenagel condensations involving ketones and ethyl cyanoacetate is studied. The reactions are diversely affected. For cyclic ketones there is a small effect on the reaction yield. However, in the case of acyclic ketones, the sensitivity of the reaction to pressure increases with increasing steric congestion of the ketone. Such a result highlights the synthetic utility of high pressure for the preparation of hindered functionalized alkenes.