Direct synthesis of alpha-hydroxy acids through selective oxidation of diols mediated by homogeneous and heterogeneous TEMPO

alpha-Hydroxy acids are pivotal components in a variety of compounds with important biological activity. Here we report an easy strategy which allows to synthesise a-hydroxy acids in a two-step oxidation process, involving first the cis-dihydroxylation of a terminal alkenes (catalyzed by ruthenium) followed by subsequent oxidation with TEMPO either dissolved in the homogeneous phase or entrapped in a sol-gel matrix. This work extends what we recently found concerning the synthesis of amino hydroxy acids by oxidation of the primary hydroxyls in aminodiols.