反应详情

温度

50 °C

A solution of dimethyl succinate (730 mg, 5.0 mmol) and 4-(tert-butyl-dimethyl-silanyloxy)-cyclohexanecarbaldehyde (1.00 g, 4.1 mmol) was added over 25 min to a 1.0M solution of potassium tert-butoxide in tert-butanol (4.4 mL. 4.4 mmol). The reaction mixture was heated at 50° C. for 50 min, cooled to RT and concentrated under vacuum. The residue was dissolved in water (25 mL) and washed with EtOAc (2×10 mL). The aqueous layer was acidified with 6 N HCl (2.0 mL, 12 mmol) and extracted with EtOAc (2×20 mL), dried (Na2SO4) and concentrated. The crude product was purified by flash chromatography (25% EtOAc/DCM) to give the title compound (560 mg) as a mixture of olefin isomers (˜1:1) and a mixture of cis and trans isomers at the cyclohexyl ring (−1:1). 1H NMR (CDCl3, 400 mHz) δ (ppm) olefin peaks at 6.88 (d, J=10.2 Hz) 6.77 (d, J=10.0 Hz) CHOTBS peaks at 3.96 ppm (br s) (cis isomer, hydrogen equitorial, 3.55 (m) (trans isomer, hydrogen axial).

1. temperaturecooled to RT
2. concentrationconcentrated under vacuum
3. dissolutionThe residue was dissolved in water (25 mL)
4. washwashed with EtOAc (2×10 mL)
5. extractionextracted with EtOAc (2×20 mL)
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated
8. customThe crude product was purified by flash chromatography (25% EtOAc/DCM)