The C-alkylation of a-methoxystyrenel and ketene acetal" by means of certain reactive organic halides shows the similarity in behavior and the high reactivity of the heteroenoid systems that are present in these two structures. It seemed of interest, therefore, to undertake a study of the effect of heat on the ketene acetals to ascertain if they would undergo the same type of thermal rearrangement as the a-alkoxystyrenes which have long been ...