Cumulated Ylides XIX. Chain-lenghthening Difunctionalization of Grignard Compounds by Reaction with Ketenylidenetriphenylphosphorane. A New Route to (E)-α,β-Unsaturated Ketones and the Queen Substance

Article abstract of DOI:10.1055/s-1988-27461

The reaction of Grignard compounds with ketenylidenetriphenylphosphorane and subsequent hydrolysis yields 2-oxoalkylidenetriphenylphosphoranes.The latter undergo Wittig reaction, whereby (E)-α,β-unsaturated ketones are obtained.An application of this strategy to the synthesis of carbonyl homologues of Lepidoptera pheromones and the queen substance is shown.