Studies on the Conversions of Diols and Cyclic Ethers. Dehydration of Alcohols and Diols on the Action of Dimethylsulfoxide

Article abstract of DOI:10.1002/hlca.19810640204

The transformations of 13 alcohols and 13 diols in the presence of a small amount dimethylsulfoxide (1/16 mol) were studied.Relationships were found between the type of the hydroxy compound and the selectivity of the transformation, and conclusions were drawn regarding the transformation mechanism.The ether formation observed with certain alcohols proceeds via a carbenium cation.The reaction conditions applied were found suitable for including water elimination from the ditertiary 1,2- and 1,3-diols (pinacol rearrangement, 1,2-elimination).From the 1,4- and 1,5-diols the corresponding oxacycloalkanes can be obtained in good yield.Cyclodehydration occurs by intramolecular nucleophilic substitution, via a concerted mechanism.The effect of DMSO is excerted directly, and proton-catalysis occurs simultaneously.