2-Ethyl-5-methyl-cyclopent-2-enon

This type of reaction can also be catalyzed by Pd complexes. Thus, e. g. hepta-1,6-diene afforded 5-ethyl-2-methyl-cyclopent-2-enone and 2-ethyl-5-methyl-cyclopent-2-enone in 16% yield when reacted with CO at 200 °C and 1000 atm in the presence of a 2% solution of diiodo-bis-(tributylphos-phine) palladium (II) [818]. 

Monomer, phthalic anhydride, diethylene glycol, C2H4, propylene, CO2 CO2, alkenes, CH4, CO, propanal methanol (major), acetone, 2-methyl propanal, methacrolein, butanal, methyl ethyl ketone, methyl isopropyl ketone, methyl isopropenyl ketone, methyl methacrylate (major), methyl prop-2-enyl ketone, toluene, di-isopropyl ketone, cyclopentanone, 2-methyl cyclopentanone, 2,5-dimethyl cyclopentanone, 2,5-di-methyl cyclopent-3-enone. Relative yields depend upon salt and copolymer composition... 

A study of the rates of isomerization of cyclohex-3-enone and cyclopent-3-enone with a variety of general bases has been made differences in effectiveness of the catalysts were attributed to electrostatic interactions in the transition state. As a result of studies on the effect of a-, and y-substituents on the equilibration of aj8- and )Sy-unsaturated bicycloalkanones, it now seems erroneous to assume that the resonance-stabilized a)3-unsaturated isomer will always predominate. Methyl ketones may be converted into diketolactones (42) by successive base-catalysed reactions with ethyl oxalate and an aldehyde (R CHO). These diketolactones lose the elements of carbon monoxide and carbon dioxide when pyrolysed in a quartz tube at 620 C to give aj8-unsaturated ketones. ... 

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