Selective Formation of a Z‑Trisubstituted Double Bond Using a 1‑(tert-Butyl)tetrazolyl Sulfone

In our effort to gain further insight into the enantioselective synthesis of the structural core of phormidolides B and C, we have discovered the formation of a Z-trisubstituted double bond. Here, we describe a highly selective process that can be applied to our target following a strategy that is based on Julia–Kocienski olefination. The use of 1-(tert-butyl)­tetrazolyl sulfone affords the construction of the Z-trisubstituted alkene with high efficiency and stereoselectivity.