(3E)-3-[(4-methoxyphenyl)methylidene]-5-methyloxolan-2-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 74 g (0.5 mol) of 4-methyl-γ-butyrolactone are added to a suspension of 27 g (0.50 mol) of sodium methoxide in 400 g of methyl tert-butyl ether and, over the course of 1 h, 68 g (0.5 mol) of anisaldehyde are added thereto with stirring at room temperature. The mixture is maintained under reflux for a further 1 h and then cooled, and 200 g of iced water are added to the mixture and the pH is adjusted to 5 using 10% sulphuric acid. After the phases have separated, the product is distilled. This gives 65 g of the desired compound in a yield of 48% of theory. The specific absorbance E{fraction (1/1)} of the novel compound according to the present invention is 1.250, measured at a wavelength of λmax 310 nm. are added The mixture is maintained under reflux for a further 1 h cooled After the phases have separated the product is distilled