The synthesis of bicyclo[2.2.2]octan-2-ones by sequential michael reactions

A preparation of bicyclo[2.2.2]octan-2-one by sequential Michael reactions.

“…Comparing this result with others described in the literature 3 we can conclude what the cyclization is favored either by the absence of a strong steric hindrance (R=H) (Scheme 1) and by increase in bond energy that accompanies the transformation of a π-bond to a σ-bond.…”

Michael type reactions mediated by NbCl5.

“…The bicyclic product analogous to 10 and 11 is not formed in the reaction with 1, possibly due to the sterical hindrance [4] produced by the extra methyl group (R 1 ≠ H).…”

Effect of Remote Polyene Bridge Methyl Substituent on Physical Properties of Dipolar Chromophores with Conformationally and Configurationally Locked Polyene Bridge

“…The bicyclic fused ring polyenones 4a (R, = H, EDG = p-N, N-dimethylaminophenyl) and 4b (R = CH 3 ; EDG = p-N, Ndimethylaminophenyl) were prepared by Michael addition of methyl vinyl ketone to the kinetic enolates of 3-substituted cyclohexenones 3a and 3b followed by intra-molecular aldol condensation of the respective products using t-BuOK in a mixture of t-BuOH and THF at room temperature. In contrast to the way this reaction has been run by others [6,8] we have used the procedure reported by Reusch and co-workers [13] which requires removal of the amine formed in the enolate generation step before the conjugate addition reaction step. This procedure was proposed to eliminate reaction of the amine with the Michael acceptor which would decrease the yield of the desired product.…”