Sulfuric Acid → HCID 71332292, compound

Participants

Reaction Steps

The mixture of the tetraester compound (B) (9.4 g, 23.5 mmol) and KOH (26.4 g, 47.0 mmol) in H2O (200 mL) was heated to reflux for 2 d. The reaction mixture was cooled to room temperature, and acidified to pH 1 by adding concentrated H2SO4. The resulting mixture was heated to reflux for 3 d, and then cooled to room temperature. The mixture was extracted with EtOAc, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product (5.8 g) was dissolved in MeOH (80 mL), and treated with concentrated H2SO4 (3.5 mL). The mixture was then stirred at room temperature for 12 h. Most of the solvent was removed under reduced pressure. The concentrate was dissolved in EtOAc, washed with H2O, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified by SiO2 flash column chromatography (hexanes:EtOAc=4:1) to give the dimethyl ester (C) (4.75 g, 20.9 mmol) in 89% yield.

Provenance & Evidence