Synthesis of alpha-hydroxy-beta-triflamido carboxylic esters through ring-opening of alkoxycarbonyl oxiranes

The oxirane ring of 3-alkyl- and 3-arylglycidic esters has been opened with trifluoromethanesulfonamide (TfNH2) under solid-liquid heterogeneous conditions. The corresponding ?-hydroxy-?-triflamido esters were produced in good yields, in a regio- and stereoselective fashion. Several reaction parameters, such as the nature of the base, the presence of a phase transfer catalyst and/or a solvent have been examined.