(a)
(b)
Figure 6: (a) HPLC chromatogram of compound 2b; (b) HPLC chromatogram of compound 2c. Peaks marked with the same sign belong to enantiomers according to their % areas. Column: Chiralpak AD-H; eluent: n-hexane: 2-propanol (85 : 15) (v : v); diode array detector.