One of the reactions that occurs, when molecule 45 is synthesized from molecule 44, is sharpless asymmetric hydroxylation. Sharpless asymmetric dihydroxylation is a stereoselective reaction that is known to be extremely reliable. This reaction is used to break a double bond and add two hydroxyl groups in a cis manner.

The reason that they attach in a cis manner is because of how the reaction occurs. Sharpless asymmetric reactions require an osmonium catalyst and a ligand. First, the ligand and the osmonium catalyst react. The ligand attacks the osmonium catalyst, which makes it a good reagent to break the double bond. The osmonium catalyst then adds to the where the double bond was in the ring. This addition creates an intermediate in the cis form because the osmonium catalyst has to add either from the top of the double bond or from the bottom of the double bond. This forms the intermediate shown below in Figure 1, which leads to the hydroxyl groups in the final product being cis to each other during the hydrolysis step.

The main reagents that are used in this article are OsO4 and (DHQ)2PHAL. The osmonium catalyst is OsO4. The ligand is (DHQ)2PHAL and assists the reaction, it is also a common reagent used when a sharpless asymmetric dihydroxylation reaction is performed.