General procedure for the synthesis of 4-(4-methoxy-2,3,6-trimethylphenyl)-but-3-en-2-one from 4-methoxy-2,3,6-trimethylbenzaldehyde and acetone: Acetone (6000 mL) was added to 4-methoxy-2,3,6-trimethylbenzaldehyde (500.3 g) and the mixture was stirred at 20-30 °C. An aqueous sodium hydroxide solution (134.8 g NaOH dissolved in 500 mL of water) was added gradually and the reaction mixture was heated to 45-50 °C with continuous stirring. The progress of the reaction was monitored by HPLC and upon completion of the reaction, the reaction mixture was cooled and the pH was adjusted with acetic acid to 4.5-5.5. Subsequently, acetone was removed by distillation, cyclohexane was added to the residue, the organic layer was washed with water, the organic layer was separated and concentrated to afford the target product, 4-(4-methoxy-2,3,6-trimethylphenyl)-but-3-en-2-one (Formula II). Yield: 80-84%.
