(2-Benzyloxyimino-cyclohexyl)-acetic acid ethyl ester (4.66 g, 16.1 mmol) was taken up in 15 mL of acetic acid (AcOH) and NaBH3CN and stirred for 72 hours. Reaction was poured into NaHCO3 and extracted into EtOAc (3×30 mL). The combined organic layers were washed once with brine, dried over Na2SO4, filtered, and concentrated. The clear oil was dissolved in 50 mL of MeOH and K2CO3 (5.55 g, 40.2 mmol) was added and the reaction stirred for 12 hours. The reaction was concentrated, the residue taken up in CHCl3, filtered, and concentrated. Purification by chromatography (SiO2, 4:1 hexanes/EtOAc) afforded 1.72 g (43%) of cis-(2-benzyloxyamino-cyclohexyl)-acetic acid ethyl ester and 0.441 g (11%) of trans-(2-benzyloxyamino-cyclohexyl)-acetic acid ethyl ester.
