(7E,9Z)-Dodeca-7,9-dien-l-y1 acetate

The pheromone is used for trapping and control of the European grapevine moth (Lubesia butrana).

Facile hydrolysis to the alcohol (2) would be expected in alkaline solution. No published information is available but generally compounds of this class are rapidly degraded biologically and their behaviour is similar to that of typical long chain alkenoic acids.

The effect of heat, sunlight, radicals and oxidants on isomerisation of the double bonds has been investigated. The compound is degraded by heating at 50 °C (6 mg remained of 100 mg after 6 days) but the process may be slowed by the addition of antioxidants. Isomerisation occurs readily in sunlight in the presence of a photosensitiser. Within 100 minutes an equilibrium mixture containing 76% E,E and 12-14% of each of the E,Z- and Z,E-isomers was formed. In the absence of photosensitiser, degradation was faster than photoequilibration. Photo-oxidation in the presence of Rose Bengal as a singlet oxygen generator gave a furan derivative (4) (see Scheme 1). This takes place after isomerisation of 1 to the E,E-isomer (3) (Shani et al., 1981).