Ethyl Acetate → (S)-methyl 2-(tert-butoxycarbonylamino)-5-oxonon-8-enoate

HRID 1171961Notes

Reaction equation

[O:1]=[C:2]1[N:6]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[C@H:5]([C:14]([O:16][CH3:17])=[O:15])[CH2:4][CH2:3]1.[CH2:18]([Mg]Br)[CH2:19][CH:20]=[CH2:21].S([O-])(O)(=O)=O.[K+].CC(=O)OCC>C1COCC1.[Cl-].[Na+].O>[C:10]([O:9][C:7]([NH:6][C@@H:5]([CH2:4][CH2:3][C:2](=[O:1])[CH2:21][CH2:20][CH:19]=[CH2:18])[C:14]([O:16][CH3:17])=[O:15])=[O:8])([CH3:13])([CH3:12])[CH3:11]

Participants

Conditions

Temperature: -78 °C

Procedure

(S)-1-tert-butyl 2-methyl 5-oxopyrrolidine-1,2-dicarboxylate (1.00 g, 4.11 mmol) in THF (20 mL) was added but-3-enylmagnesium bromide (12.3 ml, 6.17 mmol) in THF at −78° C. The reaction mixture was stirred at −78° C. for 1.5 hr and 10% potassium hydrogensulfate (20 mL) was added. The reaction mixture was then poured into a mixture of brine (20 mL) and EA (40 mL). The organic layer was separated and dried over sodium sulfate. After removal of solvent, the residue was purified by chromatography (hexane:Ethyl acetate=4:1) to give the (S)-methyl 2-(tert-butoxycarbonylamino)-5-oxonon-8-enoate as colorless oil (1.12 g, 97%). 1H NMR (400 MHz, d6-DMSO) δ7.23 (d, J=7.6 Hz, 1H), 5.79 (m, 1H), 4.93-5.03 (m, 2H), 3.92 (m, 1H), 3.61 (s, 3H), 2.48 (m, 4H), 2.20 (m, 2H), 1.88 (m, 1H), 1.69 (m, 1H), 1.38 (s, 9H).

Workup

customThe organic layer was separated
dry with materialdried over sodium sulfate
customAfter removal of solvent
customthe residue was purified by chromatography (hexane:Ethyl acetate=4:1)

Sources & evidence

ORD record: ord-172907221aa54b5aaa067a2857dc3743
Source dataset: uspto-grants-2010_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07829665B2

Reaction notes

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