(S)-3-(2-hydroxyethoxy)-4-(tripenylmethoxy)-1-butanol (500 g, 1.27 mole) was dissolved in 4.8 L of CH2Cl2, was cooled to 0° C. under N2, and triethylamine (386.4 g, 532 mL, 3.81 mole, 3.0 eq.) was added. Methanesulfonyl chloride (396.3 g, 268 mL, 3.46 mole, 2.7 eq.) was then added dropwise over 30 minutes at <5° C. The resultant reaction mixture was stirred at 0° to 5° C. for 1-2 hours and was monitored by HPLC. The reaction mixture was diluted with additional CH2Cl2 and was washed twice with 2 L of water and 2L of an aqueous saturated solution of ammonium chloride. The aqueous layers were back-extracted with 1 L of CH2Cl2 and the combined organic layer was dried (MgSO4) and evaporated in vacuo to give a crude solid that was recrystallized from 1/1 heptane/ethyl acetate to give 615 g (88%) of (S)-3-[2-[(methylsulfonyl)oxy]ethoxy]-4-(triphenylmethoxy)-1-butanol methane sulfonate in three crops as a solid. NMR. MS.
