Helicoid shiftamers.
We report calculations on the activation barriers for antarafacial [1,7]-hydrogen shifts in various helical polyenes containing saturated substructures. Based on these calculations, we predict that the barrier for analogous hydrogen shifts in the infinite system-a [1,7]-shiftamer-is only approximately 14 kcal/mol if the reactant is preorganized in an appropriate helical conformation.
Tantillo
Dean J
DJ
Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA.
Hoffmann
Roald
R