Reaction of α,β-unsaturated aldehydes with hydrogen peroxide catalysed by benzeneseleninic acids and their precursors

Oxidation of α,β-unsaturated aldehydes with hydrogen peroxide catalysed by benzeneseleninic acids and their precursors has been investigated. Bis 2-nitrophenyl diselenide has proved to be the most effective catalyst. The major products resulting from the oxidation are vinyl formates ( a ) which on hydrolysis give saturated aldehydes or ketones ( g ) having the carbon chain shortened by one carbon atom, compared with the starting alde-hydes. The minor products are formyloxyoxiranes ( b ), α-hydroxy-carbonyl ( e ) and α-formyloxycarbonyl ( f ) compounds with the carbon chain shortened by one carbon atom. Carbonyl compounds d , formally derived from an oxidative fission of the carbon-carbon double bond, have been also isolated. Diformyloxy ( 4c ) and formy-loxyacetoxy phenylmethane ( 5c ) have been isolated when cinnamaldehyde ( 4 ) or 1-phenyl-2-formyloxypropane ( 5a ) were oxidized, respectively. Possible mechanisms of formation of these products are discussed. Similar products resulted when α, β -unsaturated aldehydes were oxidized with organic peroxy acids.