Synthesis
N,N-dimethylformamide (DMF, 1 L) and potassium tert-butoxide (135.0 g, 1.2 mol) were heated to 50 °C under nitrogen atmosphere. Subsequently, 4-methyl-2-pentanone (100 ml, 50 g, 1 mol) was added to DMF and methyl 3-methylbutyrate (86.0 g, 0.75 mol) was slowly added through a dropping funnel. The reaction progress was monitored by gas chromatography (GC). After completion of the reaction, the mixture was cooled to room temperature and slowly neutralized with 20% sulfuric acid solution. After addition of water (300 ml), the mixture was layered. The organic layer containing 2,8-dimethylnonane-4,6-dione was separated and purified by vacuum distillation to give 40 g (43% yield) of pink oily product.
References
[1] Patent: JP2015/212297, 2015, A. Location in patent: Paragraph 0101; 0102
[2] Synthetic Communications, 2007, vol. 37, # 23, p. 4111 - 4115
[3] Patent: TWI612051, 2018, B. Location in patent: Paragraph 0188; 0190; 0191
