Sodium borohydride → Tert-butyl 4-fluoro-5-hydroxyazepane-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a 50 mL flask containing the product from Step B (1.0 g, 4.32 mmol) was added MeOH (20 mL), and the resulting solution was cooled to 0° C. NaBH4 (0.409 g, 10.8 mmol) was carefully added and the mixture stirred at 0° C. for 3.0 hours. The mixture was concentrated to remove the solvent and the residue was taken up in EtOAc (50 mL) and a saturated aqueous NH4Cl solution (20 mL) was added followed by water (20 mL). The layers were mixed and separated and the aqueous phase extracted with EtOAc (2×20 mL). The combined organic extracts were washed with brine and dried over Na2SO4, then filtered and concentrated. The crude product was purified by column chromatography (10% to 60% EtOAc/hexanes gradient) to provide 0.980 g (97%) of the product as a thick colorless oil that solidified to a white solid while standing overnight. The product contained of a mixture of cis and trans isomers.

Provenance & Evidence