Multifidene pheromon

Fucoserraten, ectocarpen, and multifidene are sex pheromones produced by marine brown algae. What are their systematic names (The latter two are a bit difficult make your best guess.)... 

Recent advances in gas chromatographic separations of enantiomers allow precise determination of the enantiomeric purity of the algal pheromones. The czs-disubstituted cyclopentenes, such as multifidene, viridiene, and caudoxirene, are of high optical purity [ 95% enantiomeric excess (e.e.)] whenever they have been found (32,33). The situation is different with the cyclopropanes and the cycloheptadienes, as shown in Table 2 and Figure 1. Hormosirene from female gametes or thalli of... 

The fact that the unsymmetrical product dominates in the cross-metathesis of a cyclic olefin and a terminal olefin is an advantage for the efficient synthesis of the brown algae pheromones multifidene (yield 31%) and viridiene (yield 30%) via the cross-metathesis between bicyclo[3.2.0]hepta-2,6-diene and but-l-ene or butadiene, respectively (molar ratio 1/2), in the presence of lmol% of Ru(=CHCH=CPh2)(Cl)2(PCy3)2 Scheme 15.1 (Randall 1995). 

It might be surprisingthat algae draw on pheromones as well (Fig. 8.69). Female gametes (sex cells) of numerous algae emit semiochemicals into the water, in order to attract spermatozoids. These attractants are normally polyunsaturated hydrocarbons, which are effective even at extreme dilution. (+)-Multifidene has shown a threshold concentration of 6 x 10" M. [162]... 

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