As the model experiment to explore the construction route of our synth
etic intermediat (8), the epoxy alcohol (5) was prepared by Sharpless
epoxidation including asymmetric introduction of the epoxide ring. The
cyclization of 5 to the diol (6) proceeded in 40% yield by the action
of Ti((OPr)-Pr-i)(4) at room temperature. The diol (6) having more th
an 90% enantiomeric excess was obtained from the asymmetric epoxide (5
).