To a solution of 1-tert-butyl 4-ethyl piperidine-1,4-dicarboxylate (2.0 g, 7.8 mmol) in THF (70 mL) at −78° C. was added dropwise LDA over 8 minutes, maintaining the temperature below −75° C. The mixture was stirred at −78° C. for 1 hour. 1-Chloromethoxy-2-methoxy-ethane (0.97 g. 7.8 mmol) was added dropwise while maintaining the temperature below −75° C. The mixture was stirred at −78° C. for 3 hours, and then allowed to warm slowly to room temperature overnight. The mixture was quenched with sat. aq. NH4Cl and extracted 3 times with EtOAc. The organics were combined, washed with brine, dried over MgSO4, and concentrated. Silica gel chromatography (10-20% ethyl acetate:hexanes) gave the title compound in 67% yield. MS (ES+) [M+H]+=346.
