Regioselective oxidative cleavage of benzylidene acetals: Synthesis of α- and β-benzoyloxy carboxylic acids

(Chemical Equation Presented) Ruthenium has twice the fun: The synthetic potential of the highly regio- and stereoselective title reaction, which relies on two oxidative cleavage steps promoted by RuCI3 in combination with NaIO 4 (see example; Bz = benzoyl), was demonstrated with the synthesis of biologically active cis-(2R,3S)-3-hydroxypipecolic acid from D-glucose. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.