1,2-dibenzyl 3-tert-butyl (2S,3S)-5-(2-methoxy-2-oxoethylidene)piperidine-1,2,3-tricarboxylate → (2S,3S)-3-(tert-butoxycarbonyl)-5-(2-methoxy-2-oxoethyl)piperidine-2-carboxylic acid

Participants

Reaction Steps

A solution of 1,2-dibenzyl 3-tert-butyl (2S,3S)-5-(2-methoxy-2-oxoethylidene)piperidine-1,2,3-tricarboxylate (98 mg, 0.188) in methanol (5 mL) was hydrogenated in the presence of 10% palladium on carbon (100 mg, 0.094), under balloon pressure of hydrogen, overnight. The resulting reaction mixture was filtered through a pad of celite and the precipitate was washed with methanol (2×5 mL). The volatiles were removed in-vacuo to afford 50 mg (88%) of (2S,3S)-3-(tert-butoxycarbonyl)-5-(2-methoxy-2-oxoethyl)piperidine-2-carboxylic acid as a sticky amorphous solid, which was used directly in the following coupling without further purification. LCMS (ESI): 246 (M−t-Bu+H+), 302 (M+H+).

Provenance & Evidence