Chemo-enzymatic synthesis of all isomers of 2-methylbutane-1,2,3,4-tetraol - Important contributors to atmospheric aerosols

By a combination of stereospecific osmium catalyzed oxidation of dimethyl citraconate and lipase catalysed enantioselective resolution of the formed dimethyl (2R*,3S*)-2,3-dihydroxy-2-methylbutanedioate, followed by reduction, (2R,3S)- and (2S,3R)-2-methylbutane-1,2,3,4-tetraol were isolated. Similar reactions starting with dimethyl mesaconate gave the isomers, (2R,3R)- and (2S,3S)-2-methylbutane-1,2,3,4-tetraol. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).