Highly hindered arylglyoxals axe unique among a-keto aldehydes in the great disparity in the reactivities of the two carbonyl groups. This is presumably to be ascribed to two factors,(1) the activating effect of the keto group on the aldehyde group and (2) the influence of steric hindrance on the keto group. These two effects combine to render the aldehyde group highly reactive and to block the keto group so that it is nearly inert. In order to ...
