Synthesis
GENERAL STEPS: Example 1 Preparation of (S)-3,3'-difluoro-1,1'-binaphthyl-2,2'-diol (3) Synthesis of (S)-2,2'-bis(methoxymethoxy)-1,1'-binaphthyl (4): a solution was formed by dissolving (R)-1,1'-binaphthyl-2,2'-diol (30 g, 0.10 mol) in THF (200 mL). This solution was slowly added to a stirred 60 wt% sodium hydride (NaH) slurry (10.48 g, 0.26 mol, dissolved in THF 100 mL) at 0-10 °C. The reaction temperature was kept below 10 °C and the mixture was stirred for 1 hour. Subsequently, chloromethyl methyl ether (MOMCl) (20.25 g, 0.25 mol) was added dropwise with controlled drop acceleration to maintain the temperature below 10 °C. After addition, the reaction mixture was continued to be stirred at 0-5°C for 1 hour. Upon completion of the reaction, water (100 mL) was added slowly to quench the reaction. The organic phase was separated and the aqueous phase was extracted with ethyl acetate (EtOAc, 2 x 250 mL). The organic layers were combined, washed with water (200 mL) and concentrated to give a light yellow solid. This solid was slurried in a 10:1 (v/v) hexane/EtOAc mixture, the solid was collected by filtration and dried under reduced pressure to give Product 4 as a white solid. Yield: 38.5 g, 98% yield.
References
[1] Journal of the American Chemical Society, 2003, vol. 125, # 17, p. 5139 - 5151
[2] Chemistry - A European Journal, 2009, vol. 15, # 43, p. 11450 - 11453
[3] Molecules, 2012, vol. 17, # 5, p. 5626 - 5650
[4] Angewandte Chemie - International Edition, 2015, vol. 54, # 49, p. 14748 - 14752
[5] Angew. Chem., 2015, vol. 127, # 49, p. 14961 - 14965,5
