THERMAL DECOMPOSITION OF CYCLOBUTANECARBOXALDEHYDE

In the thermal decomposition of aliphatic aldehydes free radicals are formed, while cyclobutane and its alkyl derivatives decompose in a unimolecular process. It is thus of interest to know the mechanism of the decomposition of cyclobutane carboxaldehyde containing both cyclobutyl and CHO groups. 

According to qualitative investigations, cyclobutane carboxaldehyde decomposes into acrolein and ethylene at 350-450 °C. The reaction was studied in 

The reaction is homogeneous and is of first-order between 360 and 400 °C and at initial pressures from 6 to 36 torr. The rate coefficient is 

Addition of propene, NO or toluene does not influence the rate of the reaction significantly. Lack of inhibition, the simple stoichiometry and the first-order character together indicate that cyclobutanecarboxaldehyde decomposes into ethylene and acrolein in a simple unimolccular reaction. However, the possiblity of intermediate formation of a short lived biradical cannot be ruled out. 

---