Trifluoromethanesulfonic anhydride → HCID 59192495, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of 5,7-dihydroxy-3,4-dihydro-2H-naphthalen-1-one (XXV, prepared as described in Scheme 3 above, 320 mg, 1.79 mmol) in dichloromethane (25 mL) was added diisopropylethylamine (925 mg, 7.16 mmol) at −5 to 0° C. To the resulting solution was then added trifluoromethanesulfonic anhydride (1.06 g, 3.76 mmol) dropwise over 5 minutes at this temperature. The resulting brown solution was stirred for 45 minutes at ˜0-5° C. and then warmed to room temperature and stirred for another 15 minutes. The reaction mixture was then diluted with dichloromethane (50 mL) and water (70 mL). The aqueous layer was separated and extracted with dichloromethane (25 mL). The combined organic extracts were washed with brine (100 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated under vacuum. The crude product was dissolved in dichloromethane (10 mL) and diluted with hexanes (50 mL). The brown solution was stored in the refrigerator for 15 h. The resulting solids were collected by filtration and washed with hexanes. After drying in the air, trifluoro-methanesulfonic acid 8-oxo-4-trifluoromethanesulfonyloxy-5,6,7,8-tetrahydro-naphthalen-2-yl ester (0.548 g, 69%) was obtained as a light brown solid: EI(+)-HRMS m/e calcd. for C12H8F6O7S2 (M+) 442.9616, obsd. 442.9618.

Provenance & Evidence