Base Catalyzed Isomerizations of Allyl Ethers to 1-Propenyl Ethers Using Mixed Alkali Systems

Abstract

ABSTRACT Allyl ethers were successfully isomerized to 1-propeny1 ethers using the strong inorganic bases CsOH or KOH/CaO as catalysts in the absence of solvents. Both catalyst systems required elevated temperatures and, of the two systems, KOH/CaO is more efficient and cost effective. Using KOH/CaO and conducting reactions at ∼200°C for 2–3 hours gave up to 93% isomerization to the 1-propenyl ether. Under similar conditions, no isomerization occurred when either KOH or CaO were used alone. Attempted isomerizations of 2-butenyl ethers to 1-butenyl ethers, were unsuccessful due to a side reaction that results in the elimination of butadiene from the starting material under the basic conditions. †Current address: Department of Chemistry, Vassar College, Poughkeepsie, NY 12601.