反应详情

To a solution of 1,2-dibenzyl 3-tert-butyl (2S,3S)-5-oxopiperidine-1,2,3-tricarboxylate of step 1n (850 mg) in toluene (10 mL) was added dropwise a solution of Ph3P═CH2 (0.25M in toluene/THF (3:1), 9.1 mL) at −10° C. The mixture was stirred and allowed to warm to RT during a period of 2 h. The mixture was diluted with ethyl acetate (75 mL) and washed with brine (3×25 mL). The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The residue was flash chromatographed on silica gel column to afford 1,2-dibenzyl 3-tert-butyl (2S,3S)-5-methylenepiperidine-1,2,3-tricarboxylate (546 mg). MS (ESI): 488.1 (M+Na+); 366.1 (M+H+—COO(t-Bu)).

1. washwashed with brine (3×25 mL)
2. dry with materialThe organic layer was dried over Na2SO4
3. concentrationconcentrated under reduced pressure
4. customchromatographed on silica gel column