The research described in this proposal is focused upon development of synthetic methodology for the asymmetric oxidation of olefins to vicinal diols using both osmium tetroxide and potassium permanganate. Our work to date has demonstrated that high levels of enantioselectivity can be achieved using either oxidizing agent. The chiral auxiliaries in the OsO4 oxidation are chiral diamines which function as osmium ligands for this synthetically important procedure. The potassium permanganate oxidation utilizes chiral phase transfer agents to achieve high levels of asymmetry. Future investigations designed to gain a deeper insight into the factors which regulate enantioselectivities of both reactions are detailed. With a deeper understanding of these factors, we will be able to design diamine ligands and phase transfer agents which induce a high degree of predictable asymmetry in both oxidative using catalytic amounts of BOTH osmium tetroxide and the chiral diamine without sacrificing enantioselectivity. Several NMR methods are being investigated for determining both the enantiomeric excesses of the chiral auxiliaries and the product diols. The utility of the oxidations are subsequently applied to the synthesis of the danshengdiols A and C. These abietanoid type pigments from the roots of the Chinese traditional medicine, Dan-Sheng, Salvia miltiorrhiza Bunge, have been identified as active constituents of the tanshinone preparation currently being used in Asia to treat heart disease tuberculosis, and leprosy.
