To a solution of tert-butyl 4-aminopiperidine-1-carboxylate (0.93 g, 4.65 mmol) in DCM (15 mL) was added dropwise 2M trimethylaluminum (2.8 mL, 5.7 mmol) in toluene. The resulting mixture was stirred for 15 minutes, and (S)-3-(6-bromopyridin-3-yloxy)dihydrofuran-2(3H)-one (1.0 g, 3.87 mmol) in DCM (10 mL) was added slowly over 5 minutes and the reaction stirred at ambient temperature for 2 hours. The reaction was slowly quenched by the addition of 5% tartaric acid (5 mL), saturated NaHCO3 (5 mL) and DCM (10 mL). The organic layer was separated, dried over MgSO4, filtered and concentrated in vacuo to provide (S)-tert-butyl 4-(2-(6-bromopyridin-3-yloxy)-4-hydroxybutanamido)piperidine-1-carboxylate. The crude material was taken on without a further purification.
