Hydrochloric Acid → HCID 54045028, compound

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Reaction Steps

To a solution of diisopropylamine (0.35 mL, 2.5 mmol) in 10 mL of THF at −78° C. was added n-butyllithium. The mixture was warmed to room temperature and stirred for 20 min. After cooling to −78° C., a solution of 2-[4-(4-fluoro-benzyloxy)-benzenesulfonylamino]-6-oxo-octanoic acid tert-butyl ester (1.0 g, 2.1 mmol) in 2.5 mL of THF was added dropwise. The mixture was warmed to room temperature and stirred for 3 h. After acidifying with 1M HCl, the mixture was extracted 2× into ethyl acetate, and the combined organic layers were dried over Na2SO4, filtered and concentrated in vacuo. Purification of the residue by radial chromatography (1% acetone-CH2Cl2, 2 mm plate) afforded ca. 0.37 g of the (2R,3S) diastereomer and 0.09 g of the (2R,3R) diastereomer of 1-[4-(4-fluoro-benzyloxy)-benzenesulfonyl]-3-hydroxy-3-ethyl-piperidine-2-carboxylic acid tert-butyl ester as colorless syrups:

Provenance & Evidence