[C:1]([C:4]1[C:5]([CH:15]2[CH2:18][CH2:17][CH2:16]2)=[CH:6][C:7]([CH3:14])=[C:8]([CH:13]=1)[C:9]([O:11][CH3:12])=[O:10])(=[O:3])[CH3:2].[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[C:29](Cl)(=[O:32])[CH2:30][CH3:31]>O1CCCC1>[CH:15]1([C:5]2[C:4]([C:1](=[O:3])[CH2:2][C:29](=[O:32])[CH2:30][CH3:31])=[CH:13][C:8]([C:9]([O:11][CH3:12])=[O:10])=[C:7]([CH3:14])[CH:6]=2)[CH2:16][CH2:17][CH2:18]1To a solution of methyl 5-acetyl-4-cyclobutyl-2-methylbenzoate (compound 238.1, 500 mg, 2.03 mmol, 1.00 equiv) in tetrahydrofuran (15 mL) at 0° C. was added dropwise a solution of LiHMDS (680 mg, 4.06 mmol, 2.00 equiv) in tetrahydrofuran (5 mL). After 30 min of stirring at 0° C., a solution of propanoyl chloride (280 mg, 3.03 mmol, 1.50 equiv) in tetrahydrofuran (5 mL) was added dropwise. The resulting mixture was stirred for 3 h at 15° C., and then concentrated under reduced pressure. The residue was diluted with 40 mL of ethyl acetate, washed with of brine (3×40 mL), dried (Na2SO4), and concentrated under reduced pressure. This resulted in 500 mg (crude) of the title compound as a brown oil.
Wird geladen…
