Mechanism of light-induced reductive acetylation of 1,2-naphthoquinone with acetaldehyde

Abstract

The detailed mechanism of the photochemical reaction of 1,2-naphthoquinone with acetaldehyde has been investigated. From a study of the reaction using the ¹H CIDNP technique and change of the product distribution with temperature, it was deduced that the almost all parts of the reaction proceed via an ‘in-cage’ mechanism at a low temperature, but at 20 °C at least 6.7% of the reaction proceeds via an ‘out-of-cage’ mechanism. For comparison, the addition of thermally generated acetyl radical to 1,2-naphthoquinone has also been examined.