Potassium Carbonate → (S,E)-1-tert-butyl 2-methyl 4-(methoxymethylene)pyrrolidine-1,2-dicarboxylate

Participants

Reaction Steps

Potassium carbonate (200 g, 2.17 mmol) was added to a solution of (S)-1-tert-butyl 2-methyl 4-oxopyrrolidine-1,2-dicarboxylate (88 g, 362 mmol) and dimethyl 1-diazo-2-oxopropylphosphonate (200 g, 1.04 mol) in methanol (1 L) at 0° C. and the reaction mixture was stirred at RT overnight, quenched, concentrated, poured into water, extracted with DCM, and purified by column chromatography to provide the title intermediate (18 g, 17% yield) as a yellow oil. 1H NMR (400 MHz, CDCl3): δ(ppm) 1.406-1.457 (d, 9H, J=20.4 Hz), 2.502-2.520 (m, 1H), 2.601-2.631 (m, 1H), 2.720-2.782 (m, 1H), 3.578 (s, 3H), 3.707 (s, 3H), 3.952-3.983 (m, 1H), 4.302-4.375 (m, 1H), 4.471-4.490 (m, 1H), 5.810-5.968 (m, 1H).

Provenance & Evidence