Theoretical study for ozonolysis of 1,3-butadiene

The mechanisms of the reaction of ozone with cis- and trans-1,3-butadiene are investigated at the B3LYP/6-311G(d,p) and CCSD(T)/6-311G(d,p) (single-point) computational levels. Both reactions are associated with the cycloaddition - elimination mechanism. In the O3 + cis-1,3-butadiene reaction, the initial cycloaddition product 3 will eventually lead to four most favorable products P1(cis-trans-CH2CHCHOO + H2CO), P2(cis-CH2CHCHO + H2CO2), P3(trans-CH2CHCHO + H2CO2) and P4(trans-trans-CH2CHCHOO + H2CO) which have the same calculated barrier 3.0 kcal/mol with respect to the reactant (O3 + cis-1,3-butadiene). In the O3 + trans-1,3-butadiene reaction, there are two initial cycloaddition products 4 and 8, which will lead to six favorable products P1(cis-trans-CH2CHCHOO + H2CO), P2(cis-CH2CHCHO + H2CO2), P3(trans-CH2CHCHO + H2CO2), P4(trans-trans-CH2CHCHOO + H2CO), P7(trans-cis-CH2CHCHOO + H2CO) and P8(cis-cis-CH2CHCHOO + H2CO) with similar calculated barriers ranging from 4.7 to 5.4 kcal/mol. The present paper will enrich our understanding of the chemistry of ozone towards other unsaturated hydrocarbons.