Use of Organoboranes in the Synthesis of Pheromones: A Convenient Synthesis of (Z)-6-Heneicosen-11-one and (Z)-5-Undecen-2-one, Pheromones from the Douglas Fir Tussock Moth and the Bontebok, Respectively

Abstract

Treatment of thexylborane with a halomagnesiumdialkylcuprate afforded the corresponding (B-alkyl)thexylborane in favourable yields. A second reaction with a halomagnesiumdialkenylcuprate produced the totally mixed (B-alkyl)(B-alkenyl)thexylborane. Subsequent treatment with sodium cyanide and benzoyl chloride followed by alkaline peroxide yielded an unsaturated ketone. In this way, (Z)-6-heneicosen-11-one, a sex pheromone of the Douglas Fir Tussock Moth, and (Z)-5-undecen-2-one, a pheromone from the pedal gland of the Bontebok, were prepared