Either of two isomeric ketones derived from pentane: CH₃COC₃H₇ is a flammable, colorless, clear liquid, a mixture of methyl propyl and diethyl ketones; insoluble in water, soluble in ether and alcohol; used as a solvent.

C₂H₅COC₂H₅ is a colorless, flammable liquid with acetone aroma, boiling at 101_C; soluble in alcohol and ether; used in medicine and organic synthesis.