MEK is a good choice - it can be biosynthesized from plants if you prefer.
Butanone may be produced by oxidation of 2-butanol. The dehydrogenation of 2-butanol using a catalyst is catalyzed by copper, zinc, or bronze:
CH3CH(OH)CH2CH3 → CH3C(O)CH2CH3 + H2
This is used to produce approximately 700 million kilograms yearly. Other syntheses that have been examined but not implemented include Wacker oxidation of 2-butene and oxidation of isobutylbenzene, which is analogous to the industrial production of acetone.[4]
Both liquid-phase oxidation of heavy naphtha and the Fischer-Tropsch reaction produce mixed oxygenate streams, from which 2-butanone is extracted by fractionation.[6]
Butanone is biosynthesized by some trees and found in some fruits and vegetables in small amounts. It is released to the air from car and truck exhausts.