Synthesis
1. Preparation of Compounds 1 and 3
10.0 g of compound 2 was added to 100 mL of isopropanol and 0.5 g of 5% Pd/C. The reaction was carried out at 65 °C and 2 MPa hydrogen pressure for 48 hours. Pd/C was removed by filtration, and the reaction solution was concentrated to obtain a mixture of compounds 1 and 3 (approximately 17:1 on GC). These were not separated and were directly used for subsequent reactions.
2. Preparation of Compound 1
The mixture obtained above was added to 100 mL of dichloromethane and 100 mL of water. 14.7 g of sodium bromide and 9 g of sodium bicarbonate were added. The mixture was stirred and cooled to 0~10℃, 0.2 g of TEMPO was added, and 101 g of 5% sodium hypochlorite aqueous solution was added dropwise. GC analysis showed that compound 3 was completely converted to compound 1. After separation, washing with water, and concentration, crude compound 1 was obtained with a GC purity of up to 95%. Distillation yielded compound 1 (3,3-dimethylcyclohexanone).
Uses
An interest in the boll weevil sex attractants prompted an investigation into alternative syntheses of the starting material, 3, 3-dimethylcyclohexanone.
