5-Phenyl-1-pentanol → Benzenepentanal

Participants

Reaction Conditions

Reaction Steps

A solution containing 5-phenylpentanol (10 g, 60 mmol), sodium bromide (6.45 g, 63 mmol) and TEMPO (95 mg, 0.6 mmol) in a 7:7:1 mixture of EtOAc, toluene and water (258 mL) is cooled to 0° C. With vigorous stirring, an aqueous NaOCl solution (0.35 M, 571 mL, 200 mmol) saturated with NaHCO3 (43.85 g, 520 mmol) is added in five portions separated by 10 minutes intervals. TLC analysis following the final addition indicated complete reaction. Ethanol (20 mL) is added and the mixture is partitioned between water (500 mL) and EtOAc (500 mL). Aqueous layer is extracted with EtOAc (2×500 mL) and combined organic phases are washed successively with 5% aqueous Na2S2O3 (500 mL), water (200 mL) and brine (200 mL) then dried over MgSO4 and concentrated to afford 5-phenylpentanal as an orange oil which is used without further purification assuming 100% yield. TLC analysis [pet-ether/EtOAc, 9:1, Rf (alcohol)=0.20, Rf (aldehyde)=0.60]. 1H NMR (300 MHz, CDCl3) δ 1.65 (m, 4H), 2.35 (m, 2H), 2.60 (t, 2H), 7.10-7.30 (m, 5H), 9.75 (s, 1H) ppm.

Provenance & Evidence