A novel, highly selective, and general methodology for the synthesis of 1,5-diene-containing oligoisoprenoids of all possible geometrical combinations exemplified by an iterative and convergent synthesis of coenzyme Q(10).

[reaction: see text] A truly general, versatile, and highly regio- and stereoselective methodology for the synthesis of terpenoids containing 1,5-diene units of E and/or Z geometry critically involves Pd-catalyzed homoallyl- and homopropargyl-alkenyl coupling and Zr-catalyzed carboalumination of alkynes. By using this methodology, coenzyme Q(10), (E,Z,E)-geranylgeranoil, and other natural or unnatural compounds have been synthesized efficiently.