Summary: Improved ligands render terminal olefiis good substrates for the osmium-catalyzed asymmetric di- hydroxylation (ADH) process, and the amounts of chiral ligand and osmium catalyst required diminish dramati- cally. ... Unlike the titanium-catalyzed asymmetric epoxidation (AE),' for which the inaugural ligand is still the best, the osmium-catalyzed asymmetric dihydroxylation (ADH) (Scheme I) is responsive to substantial enantioselectivity improvement through ...
