Boron trifluoride etherate → HCID 22282663、化合物

A solution of 2,3,7,8-tetrahydro-1H-furo[2,3-g]indole-2,3-dione (9.05 g, 47.9 mmol) in tetrahydrofuran (100 mL) was stirred at −20° C. under an argon atmosphere. Solid sodium borohydride was added portionwise and the reaction was stirred for 20 min at −20° C. Boron trifluoride etherate (11.9 mL, 96 mmol) was added dropwise over 90 min, then the mixture was warmed to 0° C. and stirred for 1 h. The reaction was quenched with water (100 mL) and the solution was extracted with ethyl acetate (3×150 mL). The organic extracts were combined, dried (magnesium sulphate) and concentrated in vacuo to afford a yellow solid which was purified by column chromatography [SiO2; heptane-ethyl acetate (5:1)] to afford the title compound (3.2 g, 42.8%); analytical data as described above.