Propionic Acid → methyl (4E)-octa-4,7-dienoate

78.0 g (about 0.71 mol) of 1,5-hexadien-3-ol, obtained by a Grignard reaction from allylmagnesium bromide and acrolein, were dissolved in 198.0 g (1.65 mol) of trimethyl orthoacetate and 3.0 g (0.04 mol) of propionic acid were then added. The reaction mixture was heated to 120° C. and the methanol formed during the reaction was distilled off over a 15 cm Widmer column. After 2 hours, the reaction mixture was held at 130° C. for a further 1 hour to complete the reaction and was then cooled to room temperature, diluted with 500 ml of tert-butyl methyl ether and the solution was washed twice with 100 ml of saturated sodium bicarbonate solution, dried with sodium sulphate and concentrated. Distillation of the resulting 128 g of crude product over a 20 cm Widmer column gave 51.6 g of olfactorily good methyl (E)-4,7-octadienoate of boiling point 76° C./17 mbar and with a purity of about 98%.