The product obtained from stage b) (70 mg, 0.221 mmol) was dissolved in 1 ml of DMSO, and 110 mg of powdered NaOH and then 169 mg (0.995 mmol) of n-propyl iodide were added. The reaction mixture was stirred at room temperature for 1.5 hours and then diluted with water. The crystalline precipitate obtained thereby was filtered off with suction. After drying, the material was stirred several times with n-heptane. 14.5 mg of (1S,2R)-2-(1,2-diphenyl-2-propoxyethyl)isothiazolidine 1,1-dioxide were obtained.
