Propionic Acid → Methyl (4E)-4-methyl-5-(4-methylphenyl)-4-pentenoate

Participants

Reaction Steps

Trimethyl orthoacetate (273 g, 2.24 mol) and 1-(4-methylphenyl)-2-methyl-2-propen-1-ol (91.4% pure, 39.92 g, 0.224 mol) were heated in the presence of propionic acid (0.5 ml) in an oil bath at 120°-150° C. The methanol formed during the reaction was distilled first, followed by the excess orthoacetate. The product was then freed from residual orthoacetate under vacuum and purified by column chromatography on silica gel (eluent: heptanes/ethyl acetate 25:1 to 5:1), followed by bulb-to-bulb distillation (100° C./0.001 mbar). 19.62 g (yield=40%) of the desired product were obtained.

Provenance & Evidence