Iodine → (2S,3R)-2-(N,N-Dibenzylamino)-3-tetradecanol

Participants

Reaction Conditions

Reaction Steps

To a suspension of Mg (155 mg, 6.38 mmol) and a few crystals of I2 in THF (3.1 mL), an aliquot of 1-bromoundecane (0.25 mL, 1.12 mmol) was added and the mixture was stirred at 60° C. until the red color of the solution disappeared. Then the remainder of 1-bromoundecane (0.46 mL, 2.07 mmol) was added and the reaction was stirred at room temperature for 1 h. The Grignard solution formed thereof was cooled down to 0° C. and a solution of aldehyde 4 (323.5 mg, 1.28 mmol) in THF (1.6 mL) was added via cannula. After stirring overnight at room temperature, the reaction was quenched with HCl (3N, 10 mL) extracted with EtOAc (3×10 mL), washed successively with NaHCO3 (20 mL, sat. aq.) and brine (20 mL), dried over Na2SO4 and concentrated in vacuo. The crude was purified by column chromatography on silica (100% hexane to 10:1 hexane/EtOAc) to obtain a mixture of diastereoisomers. Further purification by HPLC on silica (95:5 to 80:20 hexane/MTBE) afforded pure anti alcohol 29 as a colorless oil (205 mg, 39% yield).

Provenance & Evidence