In a two-step one-pot procedure the allylic alcohol 1 can be converted diastereoselectively into the epoxy diols (S*,R*,S*)- and (S*,R*,R*)-3 (d = 95:5), simply by adding a catalytic amount of Ti(OiPr)4 to a photooxygenated solution of the allylic alcohol 1. and stopping the reaction after the complete conversion of the hydroperoxide (S*,S*)-2. which is present in addition to the R*,S* isomer. TTP = tetraphenylporphyrin. [GRAPHICS]