DIRECT SYNTHESIS OF ALPHA,BETA-UNSATURATED NITRILES FROM ACETONITRILE AND CARBONYL-COMPOUNDS - SURVEY, CROWN EFFECTS, AND EXPERIMENTAL CONDITIONS

Detailed experimental conditions are presented for the condensation of acetonitrile with a large number of carbonyl compounds. The condensation is found to be most successful with aromatic aldehydes and diaryl ketones, substrates which yield pure α,β-unsaturated nitriles. Dialkyl ketones also condense readily under the conditions described herein but yield mixtures of double bond isomers. Aliphatic aldehydes do not condense satisfactorily, and a number of base-sensitive functional groups are incompatible with this reaction. Potassium hydroxide is found to be the most efficacious base for this reaction, and a detailed study of the condensation between acetonitrile and benzaldehyde reveals that other bases and solvents may be used, but 18-crown-6 polyether is required in some of these. The condensation is also reported for certain sterically biased ketones, and a discussion of the crown effect in these cases is presented. © 1979, American Chemical Society. All rights reserved.