Methylation of α, β, γ, δ-unsaturated-β-substituted enol phosphates with lithium dimethyl cuprate gave a mixture of (2E, 4E)-and (2Z, 4E) alkyl 3-methylalka-2, 4-dienoates and unsubstituted alkyl alka-2, 4-dienoates. An improved synthesis is described for ethyl β- safranate and the insect growth regulator hydroprene.
