Water → Bruceantin

Participants

Reaction Steps

A solution of 15-desenecioyl bruceoside-A (VI, 89.9 mg, 0.15 mmol) in dry pyridine (2 mL) was added dropwise to a solution of 3,4-dimethyl-2-pentenoyl chloride (IX, 330 mg, 2.25 mmol) in dry chloroform (2 mL). The mixture was stirred at room temperature for 20 hours until the thin layer chromatography (chloroform-methanol-water, 50:14:3) showed the disappearance of (VI), water was then added to decompose the unreacted acid chloride. The reaction product without further purification and isolation, was dissolved in dichloromethane (10 mL), and then borontrifluoride etherate (six drops) added. The reaction mixture was stirred at room temperature and examined by thin layer chromatography (chloroform-acetone, 1:1). After 4 days, the product was subjected to preparative thin layer chromatography (chloroform-acetone, 10:1) to yield pure bruceantin (V, 47.7 mg, 58% yield).

Provenance & Evidence