178306-52-0

178306-51-9

178306-52-0

The general procedure for the synthesis of (S)-2-hydroxy-3-methoxy-3,3-diphenylpropionic acid from 2-hydroxy-3-methoxy-3,3-diphenylpropionic acid was as follows: 500 mg (1.84 mmol) of (RS)-2-hydroxy-3-methoxy-3,3-diphenylpropionic acid was dissolved in 8 mL of 2-propanol, followed by addition of 135 mg (0.92 mmol) of (S)-(+)-1,2,3,4-tetrahydro-1-naphthylamine. The reaction mixture was stirred under heated reflux conditions for 1 hour, then cooled to room temperature and continued stirring for 2 hours. The precipitated crystals were collected by filtration, washed with 2-propanol and finally dried under reduced pressure. The same operations as in Example 1 were performed according to the solvents listed in Table 1.