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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of diisopropylamine (2.02 mL, 0.0144mol) in THF (30 mL) was added dropwise 1.59 M n-hexane solution of n-BuLi (9.06 mL, 0.0144mol) at minus 78° C. for over 5 min. The resulting solution was stirred for 20 min at minus 78° C. To the solution was added dropwise N-tert-butoxycarbonylproline methyl ester (3.00 g, 0.0131 mmol) in THF (30 mL) at minus 78° C. for over 5 min. The resulting solution was stirred for 10 min at minus 78° C. To the solution was added dropwise MeI (0.900 mL, 0.0144 mol) at minus 78° C. The resulting solution was stirred for 30 min at minus 78° C. The solution was quenched by the addition of sat. NH4Cl. The resulting mixture was extracted with CHCl3. The extract was washed with water, dried over Na2SO4, and evaporated in vacuo to afford 3.20 g (q.y.) N-tert-butoxycarbonyl-2-methylproline methyl ester as a yellow syrup. 1H-NMR (CDCl3) δ 1.33 (s, 9H), 1.38 (s, 3H), 1.72–2.20 (m, 4H) 3.27–3.59 (m, 2H) 3.63 (d, J=6.3 Hz, 3H).

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