Hexane → tert-Butyl (2R)-2-ethenylpyrrolidine-1-carboxylate

HRID 901338Notes

Reaction equation

[Li]CCCC.[CH3:6][CH2:7][CH2:8][CH2:9][CH2:10][CH3:11].[C:12]([O:16][C:17]([N:19]1CCC[C@@H]1C=O)=[O:18])([CH3:15])([CH3:14])[CH3:13]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[C:12]([O:16][C:17]([N:19]1[CH2:11][CH2:10][CH2:9][C@@H:8]1[CH:7]=[CH2:6])=[O:18])([CH3:15])([CH3:14])[CH3:13]

Participants

Conditions

Temperature: -78 °C

Procedure

A flask containing a suspension of methyltriphenylphosphonium bromide (24.04 g, 67.3. mmol) and THF (375 mL) is stirred under nitrogen at −78° C. To this was added a 2.5 M solution of nBuLi in hexane (26.92 mL, 67.3 mmol) over 1 h. A solution of 2-(R)-Formyl-pyrrolidine-1-carboxylic acid tert-butyl ester (6.70 g, 33.65 mmol) in THF (30 mL) is added over 10 minutes and the reaction is warmed to RT. The reaction is quenched with H20 (180 mL) and the mixture concentrated. The residue is extracted with EtOAc (3×150 mL) and the combined extracts are dried over MgSO4 and concentrated. Purification by flash chromatography 20% EtOAc/Hexanes yields the title compound as a yellow oil (5.2 g, 26.4 mmol). 1H NMR (CDCl3, 300 MHz) 5.81-5.63(m, 1H), 5.03(d, 2H), 4.40-4.15(m, 1H), 3.45-3.25(m, 2H), 2.05-1.90(m, 1H), 1.89-1.75(m, 2H), 1.74-1.61(m, 1H), 1.43(s, 9H).

Workup

additionA flask containing
temperaturethe reaction is warmed to RT
customThe reaction is quenched with H20 (180 mL)
concentrationthe mixture concentrated
extractionThe residue is extracted with EtOAc (3×150 mL)
dry with materialthe combined extracts are dried over MgSO4
concentrationconcentrated
customPurification by flash chromatography 20% EtOAc/Hexanes

Sources & evidence

ORD record: ord-7d2453a42aec480cb9771a6e8b799714
Source dataset: uspto-grants-2008_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07361663B2

Reaction notes

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