(S)-tert-butyl (3-cyclopentyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate → (S)-tert-butyl (1-cyclopentyl-3-oxopent-4-en-2-yl)carbamate

HRID 58841Notes

Reaction equation

[CH:1]1([CH2:6][C@H:7]([NH:14][C:15](=[O:21])[O:16][C:17]([CH3:20])([CH3:19])[CH3:18])[C:8](N(OC)C)=[O:9])[CH2:5][CH2:4][CH2:3][CH2:2]1.[CH:22]([Mg]Br)=[CH2:23]>C1COCC1>[CH:1]1([CH2:6][C@H:7]([NH:14][C:15](=[O:21])[O:16][C:17]([CH3:18])([CH3:19])[CH3:20])[C:8](=[O:9])[CH:22]=[CH2:23])[CH2:2][CH2:3][CH2:4][CH2:5]1

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of (S)-tert-butyl (3-cyclopentyl-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate (2.5 g, 8.3 mmol) in THF (35 mL) was added vinylmagnesium bromide (16.7 mL, 33.3 mol) at 0° C. dropwise. After completion of the addition, the reaction mixture was stirred at 0° C. for 2 h and then quenched with saturated aqueous ammonium chloride (30 mL). The resulting mixture was extracted with EtOAc (2×40 mL). The organic layers were combined, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=100:1) to afford (S)-tert-butyl (1-cyclopentyl-3-oxopent-4-en-2-yl)carbamate as a yellow oil (854 mg, 38% yield).

Workup

additionAfter completion of the addition
customquenched with saturated aqueous ammonium chloride (30 mL)
extractionThe resulting mixture was extracted with EtOAc (2×40 mL)
dry with materialdried over anhydrous sodium sulfate
concentrationconcentrated
customThe residue was purified by flash column chromatography on silica gel (petroleum ether/EtOAc=100:1)

Sources & evidence

ORD record: ord-b745fae64ca448299afa2624df5bbd6d
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09434761B2

Reaction notes

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