Lilial → (E)-3(2-Hydroxy-phenyl)-acrylic acid 3(4-tert-butyl-phenyl)-1-ethoxy-propyl ester

HRID 1870585Notes

Reaction equation

HRID 1870585 reaction equation
C([Si](C)(C)[O:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1/[CH:13]=[CH:14]/[C:15]([OH:17])=[O:16])(C)(C)C.[C:20]([C:24]1[CH:29]=[CH:28][C:27]([CH2:30][C:31](C)=[CH:32][O:33][CH2:34][CH3:35])=[CH:26][CH:25]=1)([CH3:23])([CH3:22])[CH3:21].C(C1C=CC(CC(C)C=O)=CC=1)(C)(C)C>C1(C)C=CC=CC=1.C1COCC1.CC1C=CC(S(O)(=O)=O)=CC=1>[C:20]([C:24]1[CH:25]=[CH:26][C:27]([CH2:30][CH2:31][CH:32]([O:17][C:15](=[O:16])/[CH:14]=[CH:13]/[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[OH:6])[O:33][CH2:34][CH3:35])=[CH:28][CH:29]=1)([CH3:23])([CH3:21])[CH3:22]

Participants

7

Reactant 3

HCID 228987LilialHCID 22290462(E)-3-[2(tert-Butyl-dimethyl-silanoxy)-phenyl]-acrylic acidHCID 540774831-Tert-butyl-4-(3-ethoxy-2-methyl-allyl)-benzene

Product 1

HCID 68523215(E)-3(2-Hydroxy-phenyl)-acrylic acid 3(4-tert-butyl-phenyl)-1-ethoxy-propyl esterYield 28.2%

Reagents, catalysts & solvents 3

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 3.1 g of (E)-3-[2-(tert-Butyl-dimethyl-silanoxy)-phenyl]-acrylic acid, 3.0 g of 1-tert-butyl-4-(3-ethoxy-2-methyl-allyl)-benzene, accessible from 3-(4-tert-butyl-phenyl)-2-methyl-propionaldehyde via a two step procedure according to P. D. Bartlett and A. A. Frimer, Heterocycles 11, 419-435, (1978), and 20 mg of p-TSA in 25 ml of toluene was stirred at 0° C. for 4 h and at room temperature for 14 h. The reaction mixture was partitioned between saturated sodium carbonate and hexane and the organic layer was washed with brine, dried over (Na2SO4) and evaporated to dryness to yield 5.3 g of the crude intermediate (E)-3-[2-(tert-Butyl-dimethyl-silanoxy)-phenyl]-acrylic acid 3-(4-tert-butyl-phenyl)-1-ethoxy-propyl ester as a pale yellow oil. This was dissolved in 20 ml of THF and treated at 0° C. with 3.2 g of solid TBAF-3H2O. After 30 min., the mixture was concentrated and purification by repeated flash chromatography yielded 1.2 g of the title ester (a mixture of diastereoisomers) as a pale yellow oil.

Workup

  1. customThe reaction mixture was partitioned between saturated sodium carbonate and hexane
  2. washthe organic layer was washed with brine
  3. dry with materialdried over (Na2SO4)
  4. customevaporated to dryness
  5. customto yield 5.3 g of the crude intermediate (E)-3-[2-(tert-Butyl-dimethyl-silanoxy)-phenyl]-acrylic acid 3-(4-tert-butyl-phenyl)-1-ethoxy-propyl ester as a pale yellow oil
  6. concentrationthe mixture was concentrated
  7. custompurification by repeated flash chromatography

Sources & evidence

ORD record
ord-087b5048548b4677b9435fa25842e1b8
Source dataset
uspto-grants-2000_08
Patent number
US06096918

Reaction notes

Loading…