Trimethylsilyldiazomethane → 1-tert-Butyl 2-methyl (2S)-2-methylpyrrolidine-1,2-dicarboxylate

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Reaction Steps

To a stirred solution of (S)-1-(tert-butoxycarbonyl)-2-methylpyrrolidine-2-carboxylic acid 106A in methanol (100 ml) and ether (100 ml) was added TMS-Diazomethane (80 ml) (2.0 M ether solution) dropwise at 0° C. The reaction mixture was stirred at room temperature for 2 h and the reaction mixture was concentrated. The residue was purified by flash chromatography (10% EtOAc/Hexane) to give (S)-1-tent-butyl 2-methyl 2-methylpyrrolidine-1,2-dicarboxylate 106B (28.5 g, 76% overall yield) as an oil. 1H NMR (CDCl3, 400 MHz) δ 3.69 (s, 3H), 3.42-3.56 (m, 2H), 2.13-2.17 (m, 1H), 1.83-1.93 (m, 3H), 1.49 (s, 3H), 1.39 (s, 9H).

Provenance & Evidence