Total synthesis of (-)-SNF4435 C and (+)-SNF4435 D

A convergent, biomimetic total synthesis of the immunosuppressant polyketides SNF4435 C and D is described. The synthetic pathway features a stereo- and regioselective [3,3]-sigmatropic rearrangement as well as a high-yielding Stille coupling/8,pi-6 pi electrocyclization cascade.