Tetrahydrofuran → cis-Stilbene

HRID 1354001Notes

Reaction equation

HRID 1354001 reaction equation
[PH4+].[Li][CH2:3][CH2:4][CH2:5][CH3:6].F[C:8]1[CH:9]=[C:10]([CH:13]=[C:14](OC)[C:15]=1OC)[CH:11]=O.O1C[CH2:23][CH2:22][CH2:21]1>CCCCCC.C(OCC)(=O)C>[C:10]1(/[CH:11]=[CH:6]\[C:5]2[CH:23]=[CH:22][CH:21]=[CH:3][CH:4]=2)[CH:13]=[CH:14][CH:15]=[CH:8][CH:9]=1

Participants

6

Reactant 4

HCID 8028Tetrahydrofuran2×HCID 6034473-Fluoro-4,5-dimethoxybenzaldehydeHCID 5460504PhosphoniumHCID 178418339Butyllithium

Product 1

HCID 5356785cis-StilbeneYield 34%

Reagents, catalysts & solvents 1

HCID 21226206Ethyl acetate hexaneSolvent

Procedure

To a mixture of phosphonium salt 6 (4.7 g, 6.5 mmol) and tetrahydrofuran (25 ml, cooled to −78° C.) was added n-BuLi (2.6 mL, 2.5 M, 6.5 mmol, over 5 minutes), followed by stirring for one hour. Next, 3-fluoro-4,5-dimethoxybenzaldehyde (1g, 5.4 mmol) in tetrahydrofuran (10 ml) was added (dropwise) over 30 minutes. The mixture was allowed to warm to room temperature, and stirring continued for 16 hours. The reaction was terminated by the addition of water (50 mL), the product was extracted with ethyl acetate, solvents were removed in vacuo, and the residue (1:1 E/Z, 75% yield) obtained was subjected to flash chromatography on silica gel using hexane-ethyl acetate (9:1) as eluent to afford Z-stilbene 7a (1 g, 34%) as a clear oil; 1H-NMR (300 MHz, CDCl3) δ 1.07 (s, 9H), 3.46 (s, 3H), 3.65 (s, 3H), 3.90 (s, 3H), 6.24 (d, 1H, J=12 Hz), 6.33 (d, 1H, J=12 Hz), 6.56 (m, 2H), 6.72 (m, 3H), 7.35 (m, 6H), 7.70 (m, 4H); and 12C NMR (75 MHz, CDCl3) δ 19.75, 26.65, 55.07, 55.99, 61.43, 108.26, 108.28, 109.40, 109.55, 111.74, 120.83, 122.42, 127.36, 127.46, 127.48, 127.70, 129.37, 129.50, 129.63, 130.32, 132.59, 132.66, 133.57, 134.77, 135.27, 135.83, 135.95, 144.74, 149.88, 152.91, 152.95, 154.59, 156.53; HRMS (calcd for C33H36FO4Si) [M+H]+ 543.2368, found 543.2372.

Workup

  1. stirringstirring
  2. waitcontinued for 16 hours
  3. customThe reaction was terminated by the addition of water (50 mL)
  4. extractionthe product was extracted with ethyl acetate, solvents
  5. customwere removed in vacuo
  6. customthe residue (1:1 E/Z, 75% yield) obtained

Sources & evidence

ORD record
ord-99d0a2593bf14a38bb4813a235ca7f26
Source dataset
uspto-grants-2007_05
Patent number
US07223747B2

Reaction notes

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