2,5-Hexanedione → HCID 12485849, compound

Participants

Reaction Steps

10.0 g (125 mmol) of methylcyclopentadiene were first added dropwise at 0° C. to a solution of 6.4 g (280 mmol) of sodium in 100 ml of methanol. This mixture was added dropwise at room temperature to a solution of 13.1 ml (112 mmol) of 2,5-hexanedione in 50 ml of methanol in the course of 1 hour. After the mixture had been stirred at room temperature for 4 hours, it was poured onto ice-water and acidified to pH 2. Hereafter, it was extracted with diethyl ether, dried over Na2SO4 and evaporated. The residue was chromatographed on 600 g of silica gel (long column) with hexane/methylene chloride (20:1). 0.90 g (5 %) of 3,4,7-trimethylindene (21) and 0.4 g (2%) of 2,4,7-trimethylidene (20) were obtained. For the NMR data, see Table 1.

Provenance & Evidence