NOTE: Important charges and non-bonding electrons are shown throughout the animation except during the transition phase
Click the structures and reaction arrows in sequence to view the 3D models and animations respectively
The six–membered ring contracts, by an alkyl migration from the secondary alcohol, to produce a five–membered ring. With the –N2+ group equatorial, the group best placed to migrate is the alkyl group that forms the ring as it is anti-periplanar.
P. Lewis, S. Middleton, M. Rosser and L. Stock, Aust. J. Chem., 1980, 33, 1049.
Z.-L. Song, C.-A. Fan and Y.-Q. Tu, Chem. Rev., 2011, 111, 7523–7556.