Fickle hexadienes. Manipulating the relative energies of chairlike and boatlike transition structures for the cope rearrangement.
We report calculations on various hexadienes that can assume both chairlike and boatlike conformations, yet turn out (theoretically) to have transition structures for boatlike Cope rearrangement that are equal to or lower in energy than those of alternative chairlike structures. Pathways connecting boatlike and chairlike transition states in these systems also allow for unusual and facile isomerization pathways of certain strained alkenes.
Tantillo
Dean J
DJ
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA. dt64@cornell.edu
Hoffmann
Roald
R