Ingenol → (4S,5R,6R,18R)-4,5-dihydroxy-3,8,8,15,15,18-hexamethyl-7,9-dioxapentacyclo[11.5.1.01,5.06,11.014,16]nonadeca-2,11-dien-19-one

Participants

Reaction Steps

Ingenol (1.00 g, 2.30 mmol) was dissolved in a solution of p-toluenesulphonic acid monohydrate in acetone (0.47 mg/mL, 22.5 mL). The solution was stirred at room temperature for 25 min. To this solution was added a saturated aqueous solution of NaHCO3 (0.2 mL). The obtained mixture was concentrated in vacuo. The residue was taken up in brine and extracted with ethyl acetate. The combined organic phases were dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography (heptane/ethyl acetate 19:1→heptane/ethyl acetate 0:1), giving the title compound as a white solid (616 mg, 69%). (See also: Opferkuch, H. J. et. al., Z. Naturforsch., (1981), 86b, 878-887.)

Provenance & Evidence