Preparation of the diastereomerically pure 2S-hydroxy derivative of dihydrolevoglucosenone (cyrene)

Diastereomerically pure levoglucosenone alcohol, synthesized from levoglucosenone, upon hydrogenation on Raney Ni or Pd/BaSO₄ undergoes epimerization at C² atom caused by formation of cyrene by-product and its subsequent non-specific reduction. A microbiological stereospecific technique using baker's yeast (Saccharomyces cerevisiae) has been developed levoglucosenone for cyrene reduction into cyrene alcohol and also applied to reduce 4-alkoxy and 4-benzyloxy derivatives of cyrene.