Acid-labile epoxides such as α-pinene oxide are (effectively)
synthesized in high yield from the epoxidation of terpenes with
aqueous H2O2 catalyzed by Na2WO4, [Me(n-C8H17)3N]HSO4, and
PhP(O)(OH)2 in the presence of Na2SO4 as
an auxiliary additive under organic solvent-free conditions at ambient
temperature. Origin of the salt effect is considered that the addition
of a saturated amount of Na2SO4 to aqueous
H2O2 strongly inhibited the undesired hydrolysis
of the acid-labile epoxide products, despite the highly acidic reaction
conditions.
oxidation - catalysis - epoxides - terpenoids - green chemistry