HCID 68136775, compound → Methyl 3,5-dioxo-2-styrylcyclopent-1-eneheptanoate

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Reaction Steps

To a suspension of 1.3 parts of chromium trioxide with 15 parts of pyridine is added a solution of 1.5 parts of methyl 3-hydroxy-5-oxo-2-styrylcyclopent-1-eneheptanoate in 8 parts of pyridine and the resulting reaction mixture is stirred at room temperature for about 1 hour, then is allowed to stand at that temperature for about 16 hours. To the reaction mixture ice water is then added carefully and the resulting aqueous mixture is extracted with methylene chloride. The organic extract is washed successively with dilute hydrochloric acid and dilute aqueous sodium chloride, then dried over anhydrous sodium sulfate and stripped of solvent under reduced pressure. The resulting residue is purified by dry column chromatography on silica gel containing 8% of water followed by extraction of the column with 18% ethyl acetate in benzene. The resulting crystalline product is purified further by recrystallization from benzenecyclohexane to afford methyl 3,5-dioxo-2-styrylcyclopent-1-eneheptanoate, obtained as yellow needle-like crystals melting at about 62.5°. This compound displays ultraviolet absorption maxima at about 340.5 and 250.5 millimicrons with molecular extinction coefficients of 24,000 and 10,500, respectively. It is further characterized by the following structural formula ##SPC8##

Provenance & Evidence