3-Chloropropiophenone → 5-Chloro-3-phenylpent-1-en-3-ol

HRID 271988Notes

Reaction equation

[CH:1]([Mg]Br)=[CH2:2].[Cl:5][CH2:6][CH2:7][C:8]([C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)=[O:9]>C1COCC1>[Cl:5][CH2:6][CH2:7][C:8]([C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)([OH:9])[CH:1]=[CH2:2]

Participants

Conditions

Temperature: -78 °C

Procedure

Anhydrous CeCl3 (16 g, 64.9 mmol) was stirred vigorously in 100 mL THF for 2 h 15 min. The suspension was then cooled to −78° C. and a 1 M solution of vinylmagnesiumbromide (62 mL, 62.3 mmol) was added. After 1.5 h at −78° C., a solution of 3-chloropropiophenone (7 g, 14.5 mmol) in 20 mL THF was added dropwise via cannula. The reaction mixture was stirred for 1 h, then gradually warmed to room temperature and quenched by the addition of saturated aqueous NaHCO3. Extraction into EtOAc (3×) followed by purification by silica gel chromatography (4:1 hexanes:EtOAc) afforded the 5-chloro-3-phenylpent-1-en-3-ol (7.7 g, 94%) as a yellow oil; 1H NMR (400 MHz, CDCl3): δ 7.45-7.34 (m, 4H), 7.28 (m, 1H), 6.18 (dd, 1H, J=17.2, 10.6 Hz), 5.34 (d, 1H, J=17.2 Hz), 5.23 (d, 1H, J=10.8 Hz), 3.59 (td, 1H, J=10.6, 5.5 Hz), 3.41 (td, 1H, J=10.5, 5.5 Hz), 2.40 (m, 2H), 2.0 (br. s, 1H).

Workup

temperaturegradually warmed to room temperature
customquenched by the addition of saturated aqueous NaHCO3
extractionExtraction into EtOAc (3×)
customfollowed by purification by silica gel chromatography (4:1 hexanes:EtOAc)

Sources & evidence

ORD record: ord-655224cdee934101b841b86f7dcfbe28
Source dataset: uspto-grants-2008_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07452992B2

Reaction notes

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