Ruthenium-catalysed selective transetherification of substituted vinyl ethers to acetals and aldehydes

The water-soluble ruthenium allenylidene complex [{RuCl(?-Cl)(C=C=CPh2)(TPPMS)2}2]Na4 catalyses the selective transformation of substituted linear and cyclic vinyl ethers with MeOH, under mild non acidic conditions, to give acetals, while aldehydes and ketones are obtained in a CHCl3/H2O mixture, which allows for easy recycling of the catalyst. NMR studies showed that the reaction follows a transetherification mechanism rather than simple acid-catalysed hydrolysis