Methyl-(1S,4R)-4-aminocyclopent-2-ene-1-carboxylate hydrochloride (5.50 g) was suspended in methylene chloride (60 mL), to which triphenylmethyl chloride (9.06 g, 0.0325 mol) was added. The mixture was then cooled to 0° C. Triethylamine (10.8 mL, 0.0774 mol) was then added dropwise keeping the temperature less than 10° C. Upon completion of addition, the mixture was allowed to warm to 20-25° C. The mixture was left to stir at 20-25° C. for 17 hours. The mixture was then washed with water (3×50 mL). The aqueous washes were combined and extracted with DCM (50 mL). The organics were combined and washed with brine (20 mL) and the solvent was removed under reduced pressure to afford the title compound as a brown oil (12.5 g) which was used without further purification. 1H NMR (300 MHz, CDCl3, δ): 7.58 (m, 6H), 7.27 (m, 6H), 7.18 (m, 3H), 5.57 (m, 1H), 4.93 (m, 1H), 3.76 (m, 1H), 3.65 (s, 3H), 3.18 (m, 1H), 2.11 (m, 1H), 1.90 (m, 1H) and 1.53 (m, 1H).
