Studies toward the total synthesis of scyphostatin: first entry to the highly functionalized cyclohexenone segment

The cyclohexenone segment 2 of scyphostatin (1), a potent inhibitor of neutral sphingomyelinase, was synthesized in an enantioselective manner starting from the bromo ether 5 and D-serinal derivative 3. The synthetic method features a coupling reaction of 5 with 3 to construct the asymmetric quaternary carbon center and a stereospecific epoxide ring formation as the key steps.