Ab initio investigations of the rearrangements of some β-haloalkoxides to epoxides via g3 calculations

الملخص EN

The conformational analysis of five β-chloro- and β-bromo-alkoxides had been done.

The minima and the conformational transition states were determined.

The anti conformer was found to be the most stable one.

Its percentage is more than 99.

α-Methylation increases the nuclophilicity of oxygen .Consequently, it enhances the rate of the ring closure.

In contrast to β-methylation which retards the rate of the ring closure.

This observation could be attributed to the reactivity of alkyl halides in SN2 reactions.

The rearrangements of g and g- conformers to carbonyl compounds are not feasible.

Therefore, the main rearrangement that takes place in β-haloalkoxides is the formation of epoxides.