Ethyl N-Boc-3-oxopyrrolidine-2-carboxylate

To a suspension of potassium tert-butoxide (791 mg, 7.05 mmol) in anhydrous toluene (19 mL) at 10 C a solution of 30 (1.43 g, 4.7 mmol) in toluenewas added dropwise. The reactionwas stirred at 0 C for 90 min and then it was quenched with acetic acid (500 mL), followed by the addition of a cold solution of NaH2-PO4USDH2O (2.5 g) in 25 mL of water. The layers were separated, and the aqueous phase was extracted with CHCl3. The combined organic layers were dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude product was purified by flash chromatography (silica gel, pet. ether/EtOAc 5:1, Rf 0.44) obtaining the title compound 31 as a yellow oil (497 mg, 41percent yield). 1H NMR (CDCl3, 200 MHz) major rotamer: d 4.55 and 4.47 (s, 1H), 4.27-4.22 (m, 2H), 3.91-3.84 (m) and 3.82 (t, J = 8.2 Hz) 2H, 2.69 (t, J = 8.0 Hz, 2H), 1.49 and 1.43 (s, 9H), 1.30 (t, J = 7.1 Hz, 3H). Anal. C12H19NO5 (C, H, N).

Molecular Weight:257.28
XLogP3:1.2
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:5
Exact Mass:257.12632271
Monoisotopic Mass:257.12632271
Topological Polar Surface Area:72.9
Heavy Atom Count:18
Complexity:358
Undefined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes