Carbonate formation theoretical analysis

The combination of small but significant inverse deuterium and normal 13C KIEs at Cl indicate the bond formation to this carbon atom in the early ratedetermining transition state. The observed hydrogen and carbon isotope effects in position 3 are consistent with proton transfer in the rate-determining step. Thus, from the qualitative analysis of isotope effect an early concerted pericyclic transition state can be concluded. The more detailed structure of transition state was described on the basis of theoretical calculations (Beck-e3LYP/6-31G ). 

Computer analysis indicates that there is a small electronegativity in the terminal carbon atoms of the butoxy- and n-propvl groups and progressive oxidation of the n-propyl group would also be expected to occur. In addition, there is the opportunity for (he methylene group in the 1,3-dioxole group to oxidize and open theoretically to a substituted catechol, which would then form a substituted orthoquinone with very evident brown colour, ring fission and polymer formation (Fig. 5,3). 

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