Synthesis of the entire framework of tartrolon B utilizing a silicon-tethered ring-closing metathesis strategy.

[Structure: see text] A tandem ring-closing metathesis (RCM) of silaketal-tethered dienynes gives rise to bicyclic siloxanes, which upon removal of the silicon tether afford dienediol skeletons with a stereodefined E,Z-1,3-diene motif. The implementation of this methodology has led to the construction of the entire C1-C21 linear carbon skeleton of tartrolon B.