A solution of 50 mg (0.08 mmol) of trans benzyl-N-(2,2,2-trifluoro-ethyl)-N-[4-(2,2,2-trifluoro-1-triethylsilanyloxy-1-trifluoromethyl-ethyl)-cyclohexyl]-sulfonamide (example 30.1) in 0.5 mL of THF was cooled to −78° C. and treated with 0.11 mL of a 1M solution lithium bis(trimethylsilyl)amide in THF. The mixture was allowed to reach ca −5° C. within 30 min and treated with 0.11 mL (0.1 mmol) of benzylbromide. The mixture was stirred overnight and distributed between diluted aqueous solution of HCl and Et2O. The combined organic phases were dried over Na2SO4 and the solvent was evaporated. The residue was redissolved in MeOH and treated with 0.5 mL of a 2M solution of NaOMe in MeOH. Distribution of this solution between a saturated aqueous solution of NH4Cl and Et2O, drying of the combined organic phases over Na2SO4, evaporation and column chromatography on silica gel with heptane/EtOAc 4:1 gave 50 mg (76%) of (rac) trans 1,2-diphenyl-ethanesulfonic acid (2,2,2-trifluoro-ethyl)-[4-(2,2,2-trifluoro-1-hydroxy-1-trifluoromethyl-ethyl)-cyclohexyl]-amide as a colorless foam, MS: 590 (M−H)−.
