“…Synthetic fecapentaene-12 has been prepared by several methods. In addition to those already cited, which yield, respectively, mixtures of E and Z isomers at the 5-position [3,4] the 1-position [3,5] (10), it has been prepared as the 1-Z isomer [5] (11) and the all-E isomer [3] (11,12). The availability of the isomers 3, 4, and 5 enables us to draw the following conclusions about the stereochemistry of natural fecapentaene-12.…”