Conformational behaviour induction

Attempts to predict, from precedent, the behaviour of any particular alicyclic epoxide with a Lewis acid are complicated by the great diversity of known reactions. The best that can be done is first to consider the reaction of the epoxide in isolation as likely to lead to a ketone, unless special steric or conformational features interfere with the development of the necessary transition state. Consideration must then be given to inductive or electrostatic effects of any substituents in the vicinity of the epoxide, which may prevent ketone formation. 

CR represent different conformations of the crown ether. T1+ is closer to Ag+ than to K+ or Rb+ in its behaviour. In studies of the aquation of [RhCl,] " by Hg +, Tl +, Cd +, and In + and of the equation of [RhBre] " by Tl + there is a general correlation between the rate and the stability constant of the monohalogeno-complex of the catalytic cation. The decomposition of [MeTl(OAc)2] to TlOAc and MeCOaOMe has been studied in a variety of solvents. Usually simple first-order kinetics are observed, but in deuteuriochloroform and in THE there is an initial induction period in which the solution becomes saturated with TlOAc. The authors propose a rate-determining 5n2 reaction of [AcO] with the methyl group bonded to thallium. 

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