Stereospecific Synthesis of (2Z,4E,6E)-3,7,11-Trimethyl-2,4,6,10-dodecatetraene [trans(C10)-Allofarnesene]

Abstract The stereospecific synthesis of the title acyclic sesquiterpene, isolated from Perilla frutscens f. viridis Makino (Japanese name, Aojiso) by the palladium-catalyzed cross-coupling of 2-(4,8-dimethyl-1,3,7-nonatrienyl)-1,3,2-benzodioxaborole with (Z)-2-bromo-2-butene, is described. The benzodioxaborole was prepared by the hydroboration of 4,8-dimethyl-3,7-nonadien-1-yne, newly prepared via three steps from geranial, with 1,3,2-benzodioxaborole.