Gelatin Protein‐Mediated Direct Aldol Reaction

Abstract Gelatin protein was found to catalyze the aldol reaction between cyclohexanone and different aromatic aldehydes under mild reaction conditions. The aldol additions carried out in DMSO at 37° yielded the addition products with moderate diastereoselectivities favoring the syn isomers. Appropriate control experiments demonstrated the activity of the protein in the aldol reaction. The kinetic study of the model reaction between 4‐nitrobenzaldehyde and cyclohexanone established a first‐order rate constant k=(7.4±0.5)×10−3 h−1. Moreover, the scale‐up of the process was successfully achieved at 1‐g scale in a yield comparable to that in small scale.