Synthesis of (+)-Omphadiol and (+)-Pyxidatol C

The synthesis of (+)-omphadiol and (+)-pyxidatol C was achieved through two independent strategies. For the synthesis of (+)-omphadiol, dicyclopentadienone was used as the workbench on which the three contiguous stereocenters of the cyclopentane could be introduced selectively. These include a tertiary alcohol and a selective protonation of an enolate. A ring-closing metathesis and a cyclopropanation concluded the synthesis. For the synthesis of pyxidatol C, we used the epoxide derived from (R)-linalool that was transformed to cyclopentane 23. After chain extension, another ring-closing metathesis followed by oxidation state changes and finally a cyclopropanation led to (+)-pyxidatol C.