反应详情

To a solution of 1-(5,6 dimethoxy benzofuran-2-yl)ethanone A2 (1 g, 4.545 mmol) in anhydrous Toluene added tBuOK (0.51 g, 4.545 mmol) at 0° C. under argon atmosphere and then stirred at the same temperature for 15 min to this reaction mixture geranyl bromide added drop wise. Resulting suspension stirred at the same temperature for 2 hrs. 50 ml water was added to the reaction mixture and layers were separated. Aqueous layer was extracted with ethylaectate. The combined organic extract were washed with brine and dried over Na2SO4, evaporated under reduced pressure. Chromatography of the residue on silica gel (5% EtOAc/hexanes) afforded the ketone A3 (1.69 g) in 70% yield pale yellow liquid: 1H NMR (500 MHz, CDCl3) δ 7.425 (s, 1H), 7.365 (s, 1H), 7.06 (s, 1H), 5.12-5.16 (m, 1H), 5.08-5.04 (m, 1H), 3.96 (s, 3H), 3.93 (s, 3H), 2.97-2.89 (t, 2H), 2.50-2.40 (m, 2H), 2.17-2.00 (m, 4H), 1.66 (s, 3H), 1.63 (s, 3H), 1.64 (s, 3H), 1.58 (s, 3H), ppm. Mass: ESI [M+Na]+: 379.2; Elemental anal. calcd. for C22H28O4; C, 74.13; H, 7.92. found C, 74.0; H, 5.25.

1. customResulting suspension
2. customwere separated
3. extractionAqueous layer was extracted with ethylaectate
4. extractionThe combined organic extract
5. washwere washed with brine
6. dry with materialdried over Na2SO4
7. customevaporated under reduced pressure