alpha-Bromocinnamaldehyde → (Z)-2-Bromo-1-phenylundeca-1-en-4,10-diyn-3-ol

HRID 1936916

Reaction equation

HRID 1936916 reaction equation
[CH:1]#[C:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]#[CH:8].[Li]CCCC.[C-]#[C-].[Li+].[Li+].[Br:18][C:19](=[CH:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1)[CH:20]=[O:21]>C1COCC1>[Br:18]/[C:19](/[CH:20]([OH:21])[C:1]#[C:2][CH2:3][CH2:4][CH2:5][CH2:6][C:7]#[CH:8])=[CH:22]\[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1

Participants

6

Reactant 4

HCID 21585alpha-BromocinnamaldehydeHCID 700991,7-OctadiyneHCID 178418339ButyllithiumHCID 178462446HCID 178462446, compound

Product 1

HCID 11324570(Z)-2-Bromo-1-phenylundeca-1-en-4,10-diyn-3-olYield 97%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 1,7-octadiyne (254.4 mg, 2.4 mmol) in dry THF (50 mL) cooled at −78° C. was added nBuLi (1.6 M in hexanes, 1.5 mL, 2.0 mmol) followed by stirring at the same temperature for 10 minutes. To the previously prepared lithium acetylide solution was added a solution of α-bromocinnamaldehyde Compound 1 (422.0 mg, 2.0 mmol) in dry THF (5 mL) and the resultant mixture was stirred at −78° C. for 15 minutes. The reaction was then quenched with saturated aqueous NH4Cl (20 mL) and extracted with EtOAc (50 mL×2). The combined organic layer was washed with brine, dried over anhydrous MgSO4, filtered, and concentrated under reduced pressure. The residue was purified by flash column chromatography (silica gel, 14 percent EtOAc in hexane) to give 613.1 mg (97 percent) of Compound 7: pale yellow oil; Rf=0.33 (14 percent EtOAc in hexane); IR (neat) 3397 (br), 3294, 2944, 2864, 2232, 2116, 1492, 1430, 1064 cm−1; 1H NMR (300 MHz, CDCl3) δ7.65-7.61 (m, 2H), 7.40-7.29 (m, 3H), 7.24 (s, 1H), 5.07 (br s, 1H), 2.68 (d, J=6.18 Hz, 1H, exchangeable with D2O), 2.34-2.27 (m, 2H), 2.26-2.19 (m, 2H), 1.96 (t, J=2.67 Hz, 1H), 1.74-1.62 (m, 4H); 13C NMR (75 MHz, CDCl3) δ135.4, 129.8, 129.1, 128.9, 126.8, 88.3, 84.8, 79.0, 69.4, 69.3, 61.2, 28.1, 27.9, 19.0, 18.6; MS (+CI) m/z (relative intensity) 318 (M+, 81Br, 4), 316 (M+, 79Br, 4), 220 (100).

Workup

  1. customThe reaction was then quenched with saturated aqueous NH4Cl (20 mL)
  2. extractionextracted with EtOAc (50 mL×2)
  3. washThe combined organic layer was washed with brine
  4. dry with materialdried over anhydrous MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by flash column chromatography (silica gel, 14 percent EtOAc in hexane)

Sources & evidence

ORD record
ord-026596a283f04f80859bae1a6fdac047
Source dataset
uspto-grants-2002_05
Patent number
US06391916B1

Linked notes

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