Potassium Acetate → 8-Isoprostaglandin E2

Beteiligte Stoffe

Reaktionsschritte

A solution of 1.00 g. of racemic PGE2 and 5 g. of potassium acetate in 100 ml. of 95% ethanol is allowed to stand at room temperature under nitrogen for 6 days; then is concentrated by evaporation under reduced pressure to about one third volume. The concentrated mixture is diluted with 75 ml. of cold water and dilute hydrochloric acid is added until the mixture reaches pH 3. The acidified mixture is extracted twice with ethyl acetate, then is saturated with sodium chloride and extracted once more with ethyl acetate. The ethyl acetate extracts are combined, washed with saturated aqueous sodium chloride, dried over sodium sulfate, and evaporated under reduced pressure, then dried under a stream of nitrogen to remove acetic acid from the residue. Thin layer chromatographic analysis shows that the residue comprises a mixture of racemic PGE2 and racemic 8-iso PGE2. The residue is chromatographed on 200 g. of Silicar CC4, eluting with 500 ml. 40%, 500 ml. 50%, 250 ml. 60%, and 250 ml. 100% ethyl acetate in cyclohexane, collecting 50-ml. fractions. Fractions 23-25 are combined and evaporated to give racemic 8-iso-PGE2. Fractions 27-30 are combined to give racemic PGE2.

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