The interchange reaction ROCH= CHz+ R'OH@ ROH f R'OCH= CH*, which is catalyzed b~- mercuric salts of weak acids, has been studied and found to be of wide scope and utility. It has been found that mercuric salts are specific catalysts for this reaction. A large number of other metal salts, as well as acid and base, were fount1 to be without catdy-tic activity under conditions in which catalysis by mercuric salts of weak acids was rapid and efficient. As ...