Hydrochloric Acid → 5-(Trimethylsilyl)furan-3-carbaldehyde

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Reaction Steps

n-Butyl lithium (a 2.5 m solution in hexane; 28.8 ml, 72 mmol) was added to a solution of morpholine (6.28 ml, 72 mmol) in tetrahydrofuran (700 ml) at -78° under argon. After 20 min., 3-furaldehyde (7.0 g, 72 mmol) was added. After another 20 min., sec-butyl lithium (a 1.3 m solution in cyclohexane; 55.4 ml, 72 mmol) was added dropwise and stirring continued at -78° for 7 h before chlorotrimethylsilane (27 ml, 216 mmol) was added. Stirring continued overnight (14 h) while the cooling bath was allowed to attain room temperature. The solution was poured into ice cold 10% (v/v) hydrochloric acid (200 ml) and after stirring at 0° for 10 min., the layers were separated. The aqueous phase was extracted with diethyl ether. All the organic phases were combined, dried (magnesium sulfate) and evaporated down to give a light brown oil, which was purified by flash chromatography on silica using 2% ethyl ether/hexane. Fractions with Rf of about 0.30 (silica, 10% ethyl ether/hexane) on evaporation gave 8.22 g (68%) of the title aldehyde as a light yellow oil, bp 48°-50°/0.25 torr.

Provenance & Evidence