The compound of formula (II), wherein R11 is 4-bromo, m is 0, W=O, and the bonds depicted as wavy bonds define the 7aS,6S stereoisomer, was prepared as follows. To a solution of cis-4-(4-bromo-phenoxy)-L-proline methyl ester (0.2 g) (0.66 mmol) (Preparation 4) and K2CO3 (0.09 g) (1 eq.) in 10 mL of DMF at 0° C. was added 3,5-dichlorophenyl isocyanate (0.12 g) (1 eq.). The reaction mixture was allowed to warm to 20° C. and was stirred overnight. After adding water, the mixture was extracted with EtOAc. The combined organic extracts were washed with water, dried over MgSO4, and evaporated under reduced pressure to afford after SiO2 chromatography (eluent: DCM), the above-titled compound (60 mg). Mp=116° C. NMR (DMSO, 200 MHz): 7.75 (1H, m), 7.5-7.4 (4H, d+d), 6.85 (2H, d), 5.1 (1H, m), 4.6 (1H, dd), 3.95 (1H, dd), 3.35 (1H, dd), 2.7-2.5 (1H, m), 2.25 (1H, bd).
