Synthesis of the FG ring fragment of pectenotoxins 1–9

The synthesis of the FG ring fragment common to pectenotoxins 1–9 is reported. The successful, convergent synthesis relied on high yielding routes to access two key intermediates; aldehyde 1 and phosphonium salt 2. A Z-selective Wittig reaction gave access to advanced linear precursor 3, which was converted to FG ring fragment 4 using two sequential cyclization reactions.