Poly-L-leucine catalyses the asymmetric epoxidation of enones 1–6 efficiently in a non-aqueous medium to provide the epoxy ketones 7–12 (70–91% yield; 80 to 95% ee). The strategy was used to make diltiazem 16 and the Taxol ^TM side chain 23 in single enantiomer form.

An approach to several conduritols, both naturally occurring and unnatural derivatives, is described. The key strategy of this potentially exhaustive approach relies on the bio-oxidation of chloro- or bromobenzene to their corresponding cis-diols. Subsequent synthetic manipulations enjoy extensive use of symmetry considerations in the introduction of functionalities. Complete stereo- and enantio-control is achieved in the preparation of conduritols E 5 and F 6, aminoconduritols A-1 7 and F-4 9, fluorodeoxyconduritol F 13, chlorodeoxyconduritol F 14, and deoxyconduritol E 15. A detailed discussion of the stereoelectronic parameters that control opening of epoxy alkenes of type 33 or 37 is advanced. Full experimental details are provided for all compounds.

Urea–hydrogen peroxide complex in an organic solvent and in the presence of DBU and poly-(L)-leucine causes rapid asymmetric epoxidation of the enones 1a, b and d.