3-Pentanone is a natural product that occurs in Cichorium endivia, Zingiber mioga, and other organisms for which data are available.
Diethyl ketone is a clear, colorless liquid with an acetone-like odor. Flash point 55°F. Density is less than water. Vapor is heavier than air.
Pentan-3-one is a pentanone, which is pentane with an oxo group in the 3-position. It has been isolated from Triatoma brasiliensis and Triatoma infestans. It has an effect as an animal metabolite.
3-Pentanone (also known as diethylketone) is a simple, symmetrical dialkylketone. It is a colorless liquid ketone with an acetone-like odor. Soluble in about 25 parts of water, but miscible with organic solvents.
3-Pentanone is produced by the ketodecarboxylation of propionic acid using a metal oxide catalyst:
2 CH3CH2CO2H → (CH3CH2)2CO + CO2 + H2O
In the laboratory, the reaction can be performed in a tube furnace. 
It can also be prepared by combining ethylene, CO, and H2.  Water can be used as a source of hydrogen when the reaction is catalyzed by dicobalt octacarbonyl. The proposed intermediate is the ethylene-propionyl species [CH3C(O)Co(CO)3(ethylene)], which undergoes migratory insertion to form [CH3COCH2CH2Co(CO)3]. The required hydrogen comes from the water shift reaction. For details, see  If the water shift reaction does not work, this reaction provides polymers containing alternating carbon monoxide and ethylene units. Such aliphatic polyketones are usually prepared using palladium catalysts.