Herein are described the results of t-BuOOH aided air oxidations of (-)-alp
ha -pinene, catalysed by [Co(pyridine)(2)Br-2] or [Co(4-methylpyridine)(2)B
r-2], and observations about the nature of the reactions. The use of a smal
l amount of t-BuOOH showed a clear beneficial influence on air oxidation un
der mild temperatures. Raising the temperature did not increase yields mark
edly. An increase of the hydroperoxide concentration sped up air oxidation
and brought up the amount of oxidised products, especially allylic ones. Th
e oxygen atom in oxidised products was not derived from peroxide. Instead,
the reaction needed the presence of molecular oxygen to proceed. The presen
t air oxidation is a homogeneous catalytic reaction, and the formation of v
erbenone took place via trans-verbenol. (C) 2001 Elsevier Science B.V. All
rights reserved.