According to Example 15, (R)-5-(methoxycarbonyl)-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid and 1-(3,3-diphenylpropyl)-3-methylpyrrolidin-3-ol were synthesized. To a solution of D-bis(paramethylbenzoyl)tartaric acid ((+)-Di-1,4-toluoyl-D-tartaric acid) (280 g, 0.7 mol) in isopropanol (300 mL) was added a solution of 1-(3,3-diphenylpropyl)-3-methylpyrrolidin-3-ol (280 g, 0.95 mol) in isopropanol (300 mL) at 90° C. After the solution became clear, the solution was cooled down to 30° C. slowly, and filtered to produce a white solid, which was treated with sodium hydroxide to produce (S)-1-(3,3-diphenylpropyl)-3-methylpyrrolidin-3-ol (52 g) in a yield of 18.6%.
