Tetrahydrofuran → cis-Stilbene

HRID 1786829Notes

Reaction equation

HRID 1786829 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 (1 g. 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 13C 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-615f694d84bf4a11a265e74450677301
Source dataset
uspto-grants-2009_03
Patent number
US07507851B2

Reaction notes

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