Ammonium cerium-nitrate → (S)-(+)-5-(3,4-dihydroxy-3-methyl-1-butyl)-2,3,6-trimethyl-p-benzoquinone

Beteiligte Stoffe

Reaktionsschritte

While stirring for 2 minutes at room temperature, 2.01 g of cerium ammonium nitrate in 7.5 ml of water were added dropwise to a solution of 550 mg of (S)-4-(3,5-dimethoxy-3,4,6-trimethyl-phenylethyl)-2,2,4-trimethyl-1,3-dioxolan in 7.5 ml of acetonitrile. After 2 minutes of additional stirring, the reaction mixture was extracted three times with 20 ml of chloroform each time. The combined organic extracts were dried over sodium sulfate, whereafter the solvent was removed. After chromatography of the obtained residue on silica gel with benzene/ethyl acetate (2:1 parts by volume) and ethyl acetate, there were obtained 266 mg of (S)-(+)-2,3,6-trimethyl-5-(2,2,4-trimethyl-1,3-dioxolan-4-ethyl)-p-benzoquinone and 177 mg of (S)-(+)-5-(3,4-dihydroxy-3-methyl-1-butyl)-2,3,6-trimethyl-p-benzoquinone in the form of yellow needles with a melting point of 111°-112°.

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