Borane → HCID 68524964, compound

Participants

Reaction Steps

Under an atmosphere of argon, oxazole (0.0567 g, 0.822 mmol) was taken in dry tetrahydrofuran then treated with a 1 M borane-tetrahydrofuran complex solution (0.896 mL, 0.896 mmol) and allowed to stir for 1 hour at ambient temperature. This clear solution was then cooled to −78° C. and a 2.6 M n-butyllithium solution in hexanes (0.411 mL, 1.07 mmol) was added. Upon addition of the n-butyllithium, the reaction solution changed from a clear solution to a clear yellow or dark green solution indicating lithiation of the borane-complexed oxazole. Stirring continued for 40 minutes before the addition of 7-(3-Methoxyphenyl)heptanal (0.181 g, 0.822 mmol, dissolved in 5 mL tetrahydrofuran). After 2 hours, the reaction solution was allowed to warm to ambient temperature and the reaction was quenched with a 5% solution of acetic acid in ethanol (excess) and stirred for 16 hours. The solvent was removed under reduced pressure and the residue re-dissolved in ethyl acetate. The organic phase was washed with water, saturated sodium bicarbonate, then brine and then dried over sodium sulfate. The solvent was removed under reduced pressure and flash column chromatography with silica gel (20%-50% ethyl acetate:hexanes gradient elution) gave the title compound as a light yellow oil (69%, 0.165 g): 1H NMR (600 MHz, CDCl3) δ 7.57 (s, 1H), 7.18 (t, 1H), 7.02 (s, 1H), 6.75 (d, J=7.8 Hz, 1H), 6.71 (m, 2H), 4.78 (t, 1H), 4.75 (bs, 1H), 3.78 (s, 3H), 2.57 (t, 2H), 1.89-1.91 (m, 2H), 1.57-1.62 (m, 2H), 1.42-1.45 (m, 1H), 1.30-1.40 (m, 5H); 13C NMR (150 MHz, CDCl3) δ 166.21, 159.36, 144.21, 138.49, 128.97, 126.26, 120.65, 113.98, 110.65, 67.11, 54.88, 35.77, 35.17, 31.07, 28.97, 28.94, 24.82.

Provenance & Evidence