Metabolic O-dealkylation of 1-(4′-ethylphenoxy)-3,7-dimethyl-7-methoxy or ethoxy-trans-2-octene, potent juvenoids

1-(4′-Ethylphenoxy)-3,7-dimethyl-7-methoxy or ethoxy-trans-2-octene (the ethyl-methoxide and ethyl-ethoxide) are more stable in some biological systems and less stable in others than 1-(4′-ethylphenoxy)-3,7-dimethyl-6,7-epoxy-trans-2-octene (the ethyl-epoxide). In housefly adults and mealworm pupae the persistence increases in the order of the ethyl-epoxide, -methoxide and -ethoxide but with adult stable flies the epoxide is of intermediate stability. The alkoxides are metabolized in living insects and microsomal oxidase systems of houseflies and mouse liver mainly by O-dealkylation, at a higher rate for the methoxide than the ethoxide, but benzylic oxidation of the ethyl group also occurs and is more important in the degradation of the ethyl-epoxide than the ethyl-alkoxides. The photostability on silica gel is slightly better for the ethyl-ethoxide than the -methoxide or -epoxide.