The importance of a reaction for construction of the cis, trans diene moiety of the general structures 1 and 2 is described with the molecules shown in Figure 1. In the first section, several reactions useful for construction of these dienes are presented. Such reactions are : (1) Wittig reaction; (2) Sonogashira reactions followed by cis hydrogenation; (3) - (6) cross-coupling reactions of various types. Stereoselectivity of these reactions and availability of the reaction partners required for the reactions are briefly discussed. In the remaining sections, synthesis of leukotriene B₄ (LTB₄), 10, 11-dihydro-LTB₄, didemnilactone A, korormicin, and fostriecin is presented with the observed efficiency in construction of the conjugated olefin moieties.