Abstract: Rearrangement of allyl acetals to ketene acetals is disclosed. The rearrangement is accomplished by mixing the allyl acetal with a solution of an alkali metal lower alkyl in a water-soluble primary amine. After several hours contact with the allyl acetal with the solution ketene acetal formed during the contact is separated from the reaction mixture.

Abstract: This invention concerns ortho ester polymers having repeating mer units represented by the general formulas: ##STR1## The polymers are formed by a condensation reaction between ketene acetals having a functionality of two or more and hydroxyl containing compounds having a functionality of two or more. Unlike most conventional condensation reactions, the reaction between a ketene acetal and an alcohol proceeds without the evolution of small molecule by-products which must be removed by distillation in order to achieve high molecular weight. Hence, this new process produces high molecular weight poly (ortho esters) in short reaction times, at essentially room temperature and at atmospheric pressure.