Reactivity of Tricarbonyl(pentadienyl)iron(1+) Cations: Enantioselective Synthesis of 5-HETE Methyl Ester

The syntheses of racemic 5-HETE methyl ester (1) and of 5-HETE lactone (5-HL) were accomplished in 11 steps from tricarbonyl [l-(methoxycarbonyl)pentadienyl]iron(l+) hexafluorophosphate (2). A second synthesis of 1 from 2 in five steps was also achieved. Starting with optically active 5 the synthesis of (+)-l and (-)-l in high optical purity was realized. The stereochemistry of the 6,8-diene portion and the stereochemistry of the C5 asymmetric center of 1 were controlled by the (tricarbonyl)- iron adjunct