2,3-Dibromopropene → Benzyl 4-[3-bromo-1-(ethoxycarbonyl)but-3-en-1-yl]piperidine-1-carboxylate

Participants

Reaction Steps

Lithium hexamethyldisilylazide (1.0 M in THF; 7.20 mL, 7.20 mmol) was added to solution of benzyl 4-(2-ethoxy-2-oxoethyl)piperidine-1-carboxylate (2.0 g, 6.55 mmol) in tetrahydrofuran (30 mL) at −78° C. After 40 min, 2,3-dibromoprop-1-ene (0.70 mL, 7.20 mmol) was added. After 2 h, the reaction mixture was warmed to ambient temperature. After 18 h, the mixture was quenched with saturated ammonium chloride and extracted with ethyl acetate (2×). The combined organic extracts were dried over magnesium sulfate, filtered and concentrated. Purification by silica gel chromatography (80% hexanes/ethyl acetate→40% hexanes/ethyl acetate) gave the title compound (603 mg). MS 424.0 (M).

Provenance & Evidence