Allyl bromide → N-Boc-O-allyl-L-homoserine

HRID 1797804Notes

Reaction equation

[H-].[Na+].[CH3:3][C:4]([O:7][C:8]([NH:10][C@H:11]([C:15]([OH:17])=[O:16])[CH2:12][CH2:13][OH:14])=[O:9])([CH3:6])[CH3:5].[CH2:18](Br)[CH:19]=[CH2:20]>CN(C=O)C>[CH2:20]([O:14][CH2:13][CH2:12][C@H:11]([NH:10][C:8]([O:7][C:4]([CH3:3])([CH3:5])[CH3:6])=[O:9])[C:15]([OH:17])=[O:16])[CH:19]=[CH2:18]

Participants

Conditions

Temperature: 0 °C

Procedure

To a mixture of sodium hydride (913 mg, 22.8 mmoL) in DMF at 0° C. was added N-t-Boc-L-homoserine (2 g, 9.13 mmoL). This reaction mixture was stirred at 0° C. for 15 min, and then allyl bromide (1.38 g, 11.4 mmoL) was added. The mixture was warmed up to rt, and stirred for 2 h. It was then concentrated in vacuo. The residue was diluted with water, and sequentially washed with hexane and ether. The organic layers were discarded, and the aqueous layer was carefully adjusted to pH 3 with 1 N HCl. This acidic aqueous solution was extracted with ethyl acetate. The organic phase was dried (MgSO4), and concentrated in vacuo to yield 2.2 g (93%) of (S)-4-allyloxy-2-(tert-butoxycarbonylamino)butyric acid as a colorless oil. 1H NMR (300 MHz, CD3OD) δ 1.42 (s, 9 H), 1.80-1.90 (m, 1 H), 2.04-2.16 (m, 1 H), 3.50-3.54 (m, 2 H), 3.97 (d, J=4.39 Hz, 2 H), 4.23 (dd, J=8.78, 4.39 Hz, 1 H), 5.15 (d, J=10.25 Hz, 1 H), 5.26 (dd, J=17.38, 1.65 Hz, 1 H), 5.84-5.97 (m, 1 H).

Workup

temperatureThe mixture was warmed up to rt
stirringstirred for 2 h
concentrationIt was then concentrated in vacuo
additionThe residue was diluted with water
washsequentially washed with hexane and ether
extractionThis acidic aqueous solution was extracted with ethyl acetate
dry with materialThe organic phase was dried (MgSO4)
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-cb44912e9e3a4e3a9db872eb9efbb293
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08343477B2

Reaction notes

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