Sharpless bishydroxylation

Sharpless bishydroxylation or asymmetric dihydroxylation (AD) is a chemical reaction of an alkene with osmium tetroxide to form an diol (dialcohol). Chiral products can be formed by adding quinine derivatives. A more efficient way to perform this reaction is reoxidise the osmate, which is formed in the reaction, with potassium hexacyanoferrate . This reduces the amount of the highly toxic and very expensive osmium tetroxide needed by up to 95%. It is possible to buy these mixtures as AD-mix α and AD-mix β.

The chiral diols are important for further synthesis. The introduction of chirality (chemistry) into nonchiral reactants through small amounts of a chiral catalyst is an important concept in organic synthesis.

K. Barry Sharpless won the 2001 Nobel Prize in Chemistry.