Asymmetric dihydroxylation of trans -stilbene with a new chiral ligand prepared using dihydrocinchonine and the C 2 symmetric chiral trans -9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid

The role of linker chirality on the osmium catalysed asymmetric dihydroxylation of trans-stilbene has been examined using the ligand prepared from the C 2 symmetric chiral trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid 1 and dihydrocinchonine (+)-2. Whereas the ligand prepared using (11S,12S)-(-)-1 as linker with dihydrocinchonine gave the diol in 85% ee in the asymmetric dihydroxylation of trans-stilbene, the diol was obtained in 52% ee using the ligand prepared from the (11R,12R)-(+)-1.