By using [Mn(2,6-Cl(2)TPP)Cl] (1) as a catalyst and Oxone/H(2)O(2) as an oxidant, we have developed an efficient method for erythro-selective epoxidation of acyclic allyl-substituted alkenes, including allylic alcohols, amines, and esters. Up to 9:1 erythro selectivities for terminal allyllic alkenes could be achieved, which are significantly higher than that achieved using m-CPBA as an oxidant. In addition, the synthetic utilities of this epoxidation method were highlighted in stereoselective synthesis of key anti-HIV drug intermediates and epoxidation of glycals.