The asymmetric Sharpless epoxidation of divinylcarbinol (1), a secondary, achiral allylic alcohol, is described in detail. The epoxidation proceeds with high enantio-control and diastereo-selection. The resulting 1,2-epoxy-4-pentene-3-ols 2 are equilibrated to afford the internal epoxides 5. Hydrolysis of the regioisomers 2 and 5, respectively, furnishes opposite enantiomers of erythro-4-pentenitols