Trifluoroacetic acid → 6,7,10,11,12-Pentamethoxy-3a,4,13,13a-tetrahydrodibenzo[4,5:6,7]cycloocta[1,2-c]furan-1(3H)-one

Participants

Reaction Steps

192 mg (1.44 mmole) of hydrated ruthenium oxide (soluble form) suspended in 12 ml of dichloromethane are placed in a 100 ml three-necked flask equipped with a magnetic stirrer, which is swept with argon. 1.5 ml (19 mmoles) of trifluoro acetic acid and 0.8 ml (5.7 mmoles) of trifluoro acetic anhydride are added at ambient temperature. 100 mg (0.24 mmole) of 2-(2,3,4-trimethoxybenzyl)-3-(3,4-dimethoxybenzyl)-4-butanolide dissolved in 8 ml of anhydrous dichloromethane, immediately followed by boron trifluoride etherate (0.2 ml, 1.6 mmole) are added, at ambient temperature, to the suspension which is vigorously stirred. After a few minutes, the supernatant of the solution becomes pale yellow in color. The suspension is thus maintained stirred at ambient temperature overnight, at the end of which time, monitoring by thin layer chromatography indicates the presence of a single product, with the complete disappearance of the starting product. The reaction mixture is treated with NaHCO3 and then filtered through filter paper in order to remove the solid products. The organic phase is then decanted and the aqueous phase extracted with ethyl acetate. The organic phases are then combined, dried over MgSO4 and evaporated to give a pale yellow solio which is chromatographically pure. After filtering through silica (dichloromethane), a white solid (m=98 mg, Yield: 98%) is obtained, which is comparable in all respects (chromatography, IR spectroscopy and 1H NMR spectroscopy) to the compound obtained from the plant species Steganotaenia araliacea Hochst (Umbelliferae), by high resolution analytical liquid chromatography of an ethanolic extract.

Provenance & Evidence