反应详情

To 5-benzyloxyamino-piperidine-2-carboxylic acid benzyl ester (0.806 g, 2.37 mmol) having diastereo ratio of (2S,5R)/(2S,5S)=77.4/22.6 (54.8% de), ethanol (4.75 g) and oxalic acid (0.217 g, 2.41 mmol) were added, and the obtained mixture was stirred for 2 hours. The precipitate was filtrated, washed with ethanol (0.80 g) for 2 times, and dried at 50° C. under reduced pressure to obtain 5-benzyloxyamino-piperidine-2-carboxylic acid benzyl ester oxalate (0.947 g, 2.20 mmol, yield: 93%). The diastereo ratio of this solid was (2S,5R)/(2S,5S)=87.2/12.8 (74.5% de).

1. additionwere added
2. filtrationThe precipitate was filtrated
3. washwashed with ethanol (0.80 g) for 2 times
4. customdried at 50° C. under reduced pressure