Acetophenone → 1-Phenylethanol, (S)-

Participants

Reaction Steps

(R)-3,3'-bis(2",4"-dihexyloxyphenyl)-1,1'-bi-2naphthol (42 mg, 0.05 mmol) and diethylzinc (0.01 mL, 0.1 mmol) were added to a Schlenk flask containing 10 mL of toluene (dried with Na and degassed with N2), under N2 at room temperature, to form the organozinc species. The resulting mixture was stirred at r.t. for 20 minutes. Acetophenone (0.12 mL, 1 mmol) was then added. The resulting mixture was cooled to -30° C. and 1.5 mL of catecholborane (1.5 mmol, 1M in THF) was added. Stirring was continued at this temperature for 48 h. The reaction was then quenched with 1N HCl and the aqueous layer was extracted with ether. The combined organic extracts were washed with brine until pH=7 and then dried over anhydrous Na2SO4. Purification by column chromatography on silica gel with EtOAc/hexanes (1:5) gave (S)-1-phenylethanol as a colorless liquid (107 mg, 88%). GC analysis on a β-Dex capillary column (Supelco Company), with helium as the carrier gas, a flow rate of 1 mL/min, and an increase in oven temperature from 100° C. at a rate of 1° C./min, showed an ee of 81.3%. The retention time of the (R)-isomer was 20.02 min and the retention time of the (S)-isomer was 20.68 min. 1H NMR (270 MHz, CDCl3): 1.49 (d, J=6.5, 3H), 1.79 (br, 1H), 4.90 (q, J=6.5, 1H), 7.25-7.40 (m, 5H).

Provenance & Evidence