| abstract |
Alpha, beta-unsaturated aldehydes, ketones, nitriles and esters are formed by the vapor phase condensation of saturated aldehydes, ketones, nitriles and alkyl esters of aliphatic monocarboxylic acids with formaldehyde in the presence of an unmodified silica gel catalyst. The activity and effectiveness of the catalysts is a function of their pore volume and surface area. The use of the silica gel catalyst systems gives improved conversions and yields of unsaturated product and is accompanied by retention of catalyst activity at a high level. |