A round bottomed flask was charged with (1R,3R)-methyl 1-amino-3-(4-bromophenyl)cyclopentanecarboxylate, 0.5 L-tartaric acid 2 (30 g, 80 mmol), copper(I) iodide (0.153 g, 0.804 mmol), bis(triphenylphosphine)palladium(II) dichloride (2.82 g, 4.02 mmol) and THF (200 mL). The reaction mixture was purged with nitrogen. After about 15 minutes piperidine (35.8 mL, 362 mmol) and ((prop-2-ynyloxy)methyl)benzene (11.75 g, 80 mmol) were added and the reaction mixture was heated to about 65°. After about 2 hours additional (prop-2-ynyloxy)methyl)benzene (11.75 g, 80 mmol) was added. After about 8 hours the crude reaction mixture was partitioned between EtOAc and saturated NaHCO3. The organic layer was washed with brine, dried (Na2SO4) filtered, concentrated in vacuo and purified by flash chromatography on silica gel (eluting with EtOAC/Heptane followed by EtOAc/MeOH) to provide (1R,3R)-methyl 1-amino-3-(4-(3-(benzyloxy)prop-1-ynyl)phenyl)cyclopentanecarboxylate (25 g, 68.8 mmol, 86% yield) as a brown oil.
