Acetic Acid → Tert-butyl{4-[4-(4-methoxyphenyl)-3-methylbut-3-en-1-yl]phenoxy}-dimethylsilane

Participants

Reaction Conditions

Reaction Steps

Potassium f-butylat (45 mL, 45 mmol, 1.0 equiv., 1M in THF) and 4-[4-(tert-butyldimethylsilyloxy)phenyl]butan-2-one (12.5 g, 45 mmol, 1.0 equiv.) in THF (23 mL) were added simultaneously to a solution of (m-tolyl)methyltriphenylphosphonium bromide (20.1 g, 45 mmol, 1.0 equiv.) in THF (45 mL) at 70° C. The mixture was stirred at 70° C. for 16 h. After addition of 20% aq. AcOH-solution at 25° C., the aqueous layer was extracted with hexane. The combined organic phases were washed with MeOH/H2O (4:1; 2-3×), dried (MgSO4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO2 (cyclohexane/EtOAc 99:1) to yield tert-butyl{4-[4-(4-methoxyphenyl)-3-methylbut-3-en-1-yl]phenoxy}-dimethylsilane as a light yellow oil. This compound was dissolved in THF (32 mL), n-Bu4NF (35 mL, 35 mmol, 0.8 equiv., 1.0 M in THF) was added, and the mixture was stirred at 25° C. for 1 h. After addition of H2O, the aqueous layer was extracted with MTBE (2×), the combined organic phases were washed with brine, dried (MgSO4), filtered and the filtrate was concentrated. The residue was purified by flash chromatography on SiO2 (hexane/EtOAc 9:1→4:1) to yield 7.40 g (65% over 2 steps) of the title compound as a light yellow oil.

Provenance & Evidence