Reactivity of Tricarbonyl(pentadienyl)iron Cations: Application to the Synthesis of 5-HETE Methyl Ester

The synthesis of (5S,6E,8Z,11Z,14Z)-5-hydroxy-6,8,11, 14-icosatetraenoic acid (5-HETE) methyl ester, from tricarbonyl-(1-methoxycarbonylpentadienylium)iron hexafluorophosphate and 1-lithio-1,4-decadiyne, in 11 steps is reported. The stereochemistry of the 6,8-diene portion of the molecule (E,Z) and of the C5 alcohol functionality are controlled by use of the iron(tricarbonyl) adjunct