Hydrochloric Acid → 1,2,3,4,4a,9b-Hexahydrodibenzo[b,d]furan

HRID 2220569Notes

Reaction equation

HRID 2220569 reaction equation
CC(C)([O-])C.[K+].C(O[C:10]1[CH:24]=[CH:23][C:13]2[CH:14]3[CH2:20][CH2:19][CH:18](C=O)[CH2:17][CH:15]3[O:16][C:12]=2[C:11]=1F)C.O.Cl>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C.C1COCC1>[CH2:23]1[CH:13]2[CH:12]([O:16][C:15]3[CH:17]=[CH:18][CH:19]=[CH:20][C:14]=32)[CH2:11][CH2:10][CH2:24]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 23665647Potassium tert-butoxideHCID 72483450HCID 72483450, compound

Product 1

HCID 124110971,2,3,4,4a,9b-Hexahydrodibenzo[b,d]furan

Reagents, catalysts & solvents 2

HCID 73727Phosphonium, ethyltriphenyl-, bromide (1:1)CatalystHCID 8028TetrahydrofuranSolvent3×

Procedure

10.0 g (27.0 mmol) of ethyltriphenylphosphonium bromide are initially introduced in 100 ml of THF, and 2.98 g (26.0 mmol) of potassium tert-butoxide in 40 ml of THF are added at −5° C. After 1 h at this temperature, 6.50 g (24.6 mmol) of (±)-(3R*, 4aR*, 9bS*)-7-ethoxy-6-fluoro-1,2,3,4,4a,9b-hexahydrodibenzofuran-3-carbaldehyde as a solution in 60 ml of THF are added dropwise, and the batch is stirred at room temperature for 2 h. The reaction solution is hydrolysed using water and acidified using 2 N HCl. The mixture is extracted with MTBE, and the combined organic phases are dried using sodium sulfate. The crude product remaining after removal of the solvents is filtered adsorptively (SiO2, toluene), and the filtrate is concentrated to dryness. Recrystallisation of the residue from methanol gives (±)-(3R*, 4aR*, 9bS*)-7-ethoxy-6-fluoro-3-propenyl)-1,2,3,4,4a,9b-hexahydrodibenzofuran as E/Z isomer mixture.

Workup

  1. extractionThe mixture is extracted with MTBE
  2. customthe combined organic phases are dried
  3. customafter removal of the solvents
  4. filtrationis filtered adsorptively (SiO2, toluene)
  5. concentrationthe filtrate is concentrated to dryness
  6. customRecrystallisation of the residue from methanol

Sources & evidence

ORD record
ord-7f5781f403be4961a71e8c70afd749b8
Source dataset
uspto-grants-2008_08
Patent number
US07417157B2

Reaction notes

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