Hydroxyamine hydrochloride → 2-{[(2R)-1-(benzyloxy)hex-4-en-2-yl]oxy}-N-hydroxyethanimine

HRID 1775721Notes

Reaction equation

[CH2:1]([O:8][CH2:9][C@H:10]([O:15][CH2:16][CH:17]=O)[CH2:11][CH:12]=[CH:13][CH3:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C([O-])(=O)C.[Na+].Cl.[NH2:25][OH:26]>C(O)C>[CH2:1]([O:8][CH2:9][C@H:10]([O:15][CH2:16][CH:17]=[N:25][OH:26])[CH2:11][CH:12]=[CH:13][CH3:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 60 °C

Procedure

To a mixture of {[(2R)-1-(benzyloxy)hex-4-en-2-yl]oxy}acetaldehyde (C11) (207 g, ≦0.63 mol) and sodium acetate (342 g, 4.17 mol) in aqueous ethanol (2:1 ethanol/water, 2.1 L) was added hydroxylamine hydrochloride (207 g, 2.98 mol). The reaction mixture was stirred at 60° C. for 18 hours, then concentrated in vacuo and extracted with ethyl acetate (2.0 L). The combined organic layers were dried over sodium sulfate, filtered, concentrated under reduced pressure and purified by chromatography on silica gel (Eluent: ethyl acetate in petroleum ether) to afford the product as a brown oil. By 1H NMR, this was assigned as a mixture of geometric isomers at both the oxime and olefin functional groups. Yield: 117 g, 0.444 mol, 70% over three steps. 1H NMR (400 MHz, CDCl3), characteristic peaks: δ [7.42-7.48 (m) and 6.88-6.92 (m), total 1H], 7.20-7.36 (m, 5H), 5.29-5.61 (m, 2H), [4.48-4.54 (m) and 4.41-4.45 (m), total 3H], 2.13-2.32 (m, 2H), 1.54-1.65 (m, 3H).

Workup

concentrationconcentrated in vacuo
extractionextracted with ethyl acetate (2.0 L)
dry with materialThe combined organic layers were dried over sodium sulfate
filtrationfiltered
concentrationconcentrated under reduced pressure
custompurified by chromatography on silica gel (Eluent: ethyl acetate in petroleum ether)

Sources & evidence

ORD record: ord-838d5f081e8440fd88d4cdb9c4f987b5
Source dataset: uspto-grants-2016_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09260455B2

Reaction notes

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