ja963057n_si_001.pdf (2.91 MB)
Rearrangement of Protonated Propene Oxide to Protonated Propanal
journal contribution
posted on 1997-05-21, 00:00 authored by James M. Coxon, Robert G. A. R. Maclagan, Arvi Rauk, Aaron J. Thorpe, Dale WhalenCalculations at the MP2/6-31G*//MP2/6-31G* level show
there are concerted asynchronous pathways
connecting protonated propene oxide and protonated propanal. With
cleavage of the C−O bond of protonated propene
oxide, the preference for rotation of oxygen away from the more
hindered face of the oxirane plane containing the
methyl group is quantified as 2 kcal/mol. This pathway involves
two distinct steps; first, rupture of the oxirane and,
second, hydride migration. The latter does not commence until
rupture of the C−O bond is complete. The
combination
of these two steps defines a concerted asynchronous rearrangement
pathway. The reaction is predicted to show a
20:1 preference for migration of the proton trans to the
methyl over the cis.