(S)-tert-butyl 3-isopropoxypyrrolidine-1-carboxylate synthesis

Yield:1061682-71-0 41%

Reaction Conditions:

with silver(l) oxide at 20 - 40; for 48 h;

Steps:

5.L Method L: (S)-tert-butyl 3-isopropoxypyrrolidine-1-carboxylate

Method L: (S)-tert-butyl 3-isopropoxypyrrolidine-1-carboxylate To a stirred solution of (S)-(+)-tert-butyl-3-hydroxypyrrolidine-1-carboxylate (1.0 g, 5.34 mmol) in isopropyl iodide (15 ml) was added silver(I) oxide (1.49 g, 6.41 mmol). The reaction mixture stirred at room temperature for 24 hours then heated at 40° C. for a further 24 hours. The reaction mixture was then cooled down to room temperature and filtered through a pad of Celite, washing with diethyl ether (2*10 ml). The filtrate was concentrated in vacuo and the residue purified on silica gel by flash column chromatography eluding with 20% ethyl acetate in petroleum ether to afford the title compound as a colourless oil (0.50 g, 41% yield). ¹H NMR (CDCl₃, 400 MHz) δ 1.02 and 1.07 (6H, d, rotamers), 1.32-1.45 (2H, m), 1.47 and 1.48 (9H, s, rotamers), 1.51-1.65 (1H, m), 1.67-1.95 (3H, m), 2.01-2.12 (2H, m), 2.66-2.76 (3H, m), 3.25-3.35 (2H, m), 4.05-4.25 (2H, m).

References:

US2010/137305,2010,A1 Location in patent:Page/Page column 33