Benzaldehyde → 1-Phenylpropyl acetate

Participants

Reaction Steps

To a vial containing aminoalcohol 1 (0.05 g, 0.17 mmol) prepared as in Example 1 was added a solution containing benzaldehyde (0.32 g, 3.0 mmol), toluene (3.0 mL), and 1 M diethylzinc in hexane (6.0 mL). After 3 days at room temperature, acetic anhydride (1.2 mL, 13 mmol) was added. After 2 additional days, the mixture was diluted in ether (50 mL) and the reaction was quenched by dropwise addition of half-saturated aqueous ammonium chloride (50 mL). The ether layer separated and the aqueous layer was further extracted with ether (2×50 mL). The combined ether layers were dried over magnesium sulfate whereupon the solvent was removed at reduced pressure. The residue was purified by flash chromatography on 220-400 mesh silica with 90% hexane and 10% ethyl acetate as eluant. The product (+)-1-phenylpropyl acetate (0.46 g, 86%) was isolated as a colorless liquid by distillation of the solvent at reduced pressure. Anal. for C11H14O2. Calcd: C, 74.13; H, 7.92; found: C, 74.32; H, 7.82. 1H NMR (CDCl3/TMS): δ 0.87 (t, 3 H, J=7), 1.79, (m, 1 H), 1.90 (m, 1 H), 2.06 (s, 3 H), 5.66 (t, 1 H, J=7), 7.1-7.7 (m, 5 H). 13C NMR (CDCl3/TMS): δ 9.89, 21.23, 29.30, 77.66, 126.76, 128.81, 128.57, 140.58, 170.36. [α]D25=+103.4, c=2.15 g/100 mL chloroform. Chiral capillary gas chromatographic analysis at 120° C. on Cyclodex B stationary phase (J & W Scientific) indicated that the enantiomeric excess of the product was 98%.

Provenance & Evidence