(2S,4R)-4-Hydroxypyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester → 1-tert-butyl 2-methyl (2S)-4-oxopyrrolidine-1,2-dicarboxylate

Participants

Reaction Steps

150 g of 1-tert-butyl 2-methyl(2S,4R)-4-hydroxypyrrolidine-1,2-dicarboxylate, 264 g of pyridinium chlorochromate, and 75 g of celite were stirred in 2 L of chloroform at room temperature. During this stirring, another 100 g of pyridinium chlorochromate was added, and the reaction mixture was stirred for a total of 7 days. The reaction solution was filtered through celite (washed with 500 mL of chloroform), and the filtrate was concentrated under reduced pressure to obtain 197 g of black oil. The residue thus obtained was purified by column chromatography (silica gel 60, mobile phase: ethyl acetate/n-hexane=2/1; v/v) to obtain 119 g of the titled compound (yellow oily substance).

Provenance & Evidence