The general procedure for the synthesis of triphenylmethyl-(S)-glycidyl ethers from triphenylchloromethane and (R)-oxirane-2-methanol is as follows: the preparation of triphenylmethyl-protected glycidyl alcohol derivative 401 was carried out with reference to the literature methodology (Schweizer et al., Synthesis 2007, 3807-3814; this literature is incorporated herein by reference). The procedure was as follows: under argon protection, (β)-glycidol (5.0 g, 61 mmol) was dissolved in CH2Cl2 (30 mL) and slowly added to a stirred solution of triamcinolone chloride (18.6 g, 66.8 mmol) and triethylamine (16.9 mL, 122 mmol) in CH2Cl2 (67 mL) via a syringe under ice-bath conditions. After the addition of glycidol was completed, DMAP (742 mg, 6.08 mmol) was added to the reaction mixture. Subsequently, the reaction system was gradually warmed up to room temperature. After the reaction was carried out for 14 hours, the reaction mixture was diluted with 300 mL of saturated NH4Cl aqueous solution. It was further diluted with water to about 1 L to dissolve the precipitated salt. The product was extracted from the quenched solution with Et2O (3×); the combined ether layers were washed with brine, dried over MgSO4, filtered through filter paper, and concentrated by rotary evaporation to give a white solid. The crude product was purified by recrystallization from boiling MeOH (200 mL), resulting in the target product 401 (14.1 g, 73% yield) as white crystals. The NMR analysis of the obtained product was in agreement with literature reports (Schweizer et al., Synthesis 2007, 3807-3814).
