Tetrahydrofuran → [5-((e)-5-Ethyl-1-methyl-5-triethylsilanyloxyhept-1-enyl)-2-thienyl]methanol

HRID 49321Notes

Reaction equation

HRID 49321 reaction equation
Br[C:2]1[S:6][C:5](/[C:7](/[CH3:24])=[CH:8]/[CH2:9][CH2:10][C:11]([CH2:22][CH3:23])([CH2:20][CH3:21])[O:12][Si:13]([CH2:18][CH3:19])([CH2:16][CH3:17])[CH2:14][CH3:15])=[CH:4][CH:3]=1.C([Li])CCC.[BH4-].[Na+].[Cl-].[NH4+].C1C[O:37][CH2:36]C1>CN(C=O)C>[CH2:20]([C:11]([O:12][Si:13]([CH2:18][CH3:19])([CH2:16][CH3:17])[CH2:14][CH3:15])([CH2:22][CH3:23])[CH2:10][CH2:9]/[CH:8]=[C:7](/[C:5]1[S:6][C:2]([CH2:36][OH:37])=[CH:3][CH:4]=1)\[CH3:24])[CH3:21]

Participants

7

Reactant 5

HCID 8028TetrahydrofuranHCID 25517Ammonium ChlorideHCID 4311764Sodium borohydrideHCID 17934815[(e)-5-(5-Bromo-2-thienyl)-1,1-diethylhex-4-enyloxy]triethylsilaneHCID 178418339Butyllithium

Product 1

HCID 20636308[5-((e)-5-Ethyl-1-methyl-5-triethylsilanyloxyhept-1-enyl)-2-thienyl]methanol

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
-78 °C

Procedure

2.8 g (6.5 mmol) of [(E)-5-(5-bromo-2-thienyl)-1,1-diethylhex-4-enyloxy]triethylsilane are dissolved in 50 mL of anhydrous THF and the mixture is then cooled to −78° C. 2.9 mL (7.1 mmol) of 2.5 M butyllithium solution are then added, after which the reaction medium is stirred for 15 minutes. 0.55 mL of anhydrous DMF is then added, after which the reaction medium is warmed to room temperature and stirred for 1 h. After treatment with saturated ammonium chloride solution and then extraction with ethyl acetate, the organic phases are combined, dried and concentrated under reduced pressure. The residue containing the desired 5-((E)-5-ethyl-1-methyl-5-triethylsilanyloxyhept-1-enyl)thiophene-2-carbaldehyde is then dissolved in 50 mL of anhydrous methanol, after which 150 mg (3.9 mmol) of sodium borohydride are added in two portions. After stirring for 10 minutes, the medium is treated with ammonium chloride solution and extracted with ethyl ether. The organic phases are combined, dried and concentrated under reduced pressure. After purification by chromatography on a column of silica, a yellow oil is obtained (m=1.76 g; Y=71%).

Workup

  1. customafter which the reaction
  2. temperaturemedium is warmed to room temperature
  3. stirringstirred for 1 h
  4. extractionAfter treatment with saturated ammonium chloride solution and then extraction with ethyl acetate
  5. customdried
  6. concentrationconcentrated under reduced pressure
  7. additionThe residue containing the desired 5-((E)-5-ethyl-1-methyl-5-triethylsilanyloxyhept-1-enyl)thiophene-2-carbaldehyde
  8. dissolutionis then dissolved in 50 mL of anhydrous methanol
  9. stirringAfter stirring for 10 minutes
  10. extractionextracted with ethyl ether
  11. customdried
  12. concentrationconcentrated under reduced pressure
  13. customAfter purification by chromatography on a column of silica
  14. customa yellow oil is obtained (m=1.76 g; Y=71%)

Sources & evidence

ORD record
ord-2ea3cb52dab5476da01125be5ef7f95f
Source dataset
uspto-grants-2004_03
Patent number
US06706725B1

Reaction notes

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