Acetylacetone → HCID 68723788, compound

Participants

Reaction Steps

In a Dean-Stark apparatus, a mixture of 1-cyclopentylidenepropan-2-one/1-cyclopentenylpropan-2-one (25:75, 600 g, 4.83 mol), acetylacetone (493 g, 4.83 mol), and zinc chloride (164.6 g, 1.21 mol) in benzene (500 ml) and heptane (500 ml) was heated at reflux for 2.5 d (44 ml water collected). The reaction mixture was poured into ice/water (1.5 l) and extracted with cyclohexane (0.6 l). The organic phase was washed with water (1 l), with a saturated aqueous solution of NaHCO3 (0.5 l), twice with a saturated aqueous solution of NaCl (1 l and 0.5 l), dried (100 g MgSO4), and concentrated (till 60° C./30 mbar). Vigreux-Distillation (0.08 mbar, bath temperature 180° C., head temp. 120-130° C.) of the crude product (615 g) followed by FC (2 kg SiO2, hexane/MTBE 2:1) gave 10-acetyl-9-methylspiro[4.5]dec-8-en-7-one (20.7 g, 2.1%). Boiling point: 150° C. (0.09 mbar).

Provenance & Evidence