C([Li])CCC.Br[C:7]1[CH:12]=[CH:11][C:10]([Br:13])=[CH:9][CH:8]=1.[C:14]1(=[O:18])[CH2:17][CH2:16][CH2:15]1>C1COCC1>[Br:13][C:10]1[CH:11]=[CH:12][C:7]([C:14]2([OH:18])[CH2:17][CH2:16][CH2:15]2)=[CH:8][CH:9]=1n-Butyllithium (1.2 mL 1.92 mmol, 1.6 M/hexanes) was added to a −78° C. solution of 1,4-dibromobenzene (489 mg, 2.07 mmol) in THF (4.2 mL). After 30 min., a solution of cyclobutanone (141 mg, 2.01 mmol) in 1 mL THF was added by cannula, rinsing with 0.5 mL THF. The reaction was allowed to warm to room temperature and after 2 h, saturated NH4Cl solution was added. The resulting mixture was extracted with ethyl acetate (3×30 mL) and the combined ethyl acetate solution was washed with brine. The solution was then dried (Na2SO4), filtered and evaporated. Purification by flash chromatography on silica gel (5%→10% ethyl acetate/hexanes) gave 3-1 (235 mg, 54%).
読み込み中…