p-Toluenesulfonic acid → But-2-enoic acid 1,5-dimethyl-hex-4-enyl ester

関与物質

反応条件

反応手順

6-Methyl-hept-5-en-2-ol (256 g, commercially available at IFF), crotonic acid (193 g), PTSA (2.5 g), and toluene (250 mL) were charged into a 2-L reaction flask fitted with a mechanical stirrer, a thermocouple, a Dean-Stark trap, and a condenser. The reaction mixture was heated to reflux at about 110-133° C. Water was removed azeotropically. The reaction was aged at reflux for about 6 hours until no more water evolved. The reaction mixture was cooled to under 60° C. and quenched with water (300 mL). The aqueous and organic layers were split. The organic layer was subsequently washed with sodium carbonate (2%, 300 mL) and further fractional distilled to provide but-2-enoic acid 1,5-dimethyl-hex-4-enyl ester (204 g) with a boiling point of 98° C. at 4 mmHg.

情報源と証拠