Lithium borohydride → 5-Ethyl-6-(4-hydroxy-3-methyl-but-2-enyl)4-methyl-7-(2-trimethylsilanyl-ethoxy)-3H-isobenzofuran-1-one

HRID 33006Notes

Reaction equation

HRID 33006 reaction equation
[CH2:1]([C:3]1[C:11]([CH3:12])=[C:10]2[C:6]([C:7](=[O:13])[O:8][CH2:9]2)=[C:5]([O:14][CH2:15][CH2:16][Si:17]([CH3:20])([CH3:19])[CH3:18])[C:4]=1[CH2:21][CH:22]=[C:23]([CH3:26])[CH:24]=[O:25])[CH3:2].[BH4-].[Li+]>CO.CO.O.C1COCC1>[CH2:1]([C:3]1[C:11]([CH3:12])=[C:10]2[C:6](=[C:5]([O:14][CH2:15][CH2:16][Si:17]([CH3:18])([CH3:19])[CH3:20])[C:4]=1[CH2:21][CH:22]=[C:23]([CH3:26])[CH2:24][OH:25])[C:7](=[O:13])[O:8][CH2:9]2)[CH3:2]

Participants

6

Reactant 2

HCID 4148881Lithium borohydrideHCID 725636044-[6-Ethyl-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-2-methyl-but-2-enal

Product 1

HCID 670098805-Ethyl-6-(4-hydroxy-3-methyl-but-2-enyl)4-methyl-7-(2-trimethylsilanyl-ethoxy)-3H-isobenzofuran-1-oneYield 73.4%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolventHCID 22242641Methanol--water (1/1)Solvent

Conditions

Temperature
0 °C

Procedure

4-[6-Ethyl-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-2-methyl-but-2-enal (77.6 mg, 0.207 mmol) was dissolved in MeOH (4 mL). A solution of CeCl3 (51.1 mg, 0.207 mmol) in MeOH/water (9/1, 0.66 mL) was added and the solution was cooled to 0° C. A solution of lithium borohydride in THF (2M, 0.105 mL) was added dropwise. After 15 minutes, the reaction was quenched with 1N HCl (0.5 mL). The MeOH was removed in vacuo and the crude material was partitioned between DCM and water. The aqueous layer was extracted with DCM and the combined organic layers were washed with sodium bicarbonate solution and dried over sodium sulfate. Filtration and evaporation of solvents yielded a crude oil, which was purified by silica get chromatography to provide 57.2 mg (73%) of the desired product. 1H NMR (300 MHz, CDCl3): δ=0.04 (s, 9H), 1.15 (t, J=7.8 Hz, 3H), 1.26 (m, 2H), 1.86 (s, 3H), 2.19 (s, 3H), 2.72 (q, J=7.8 Hz, 2H), 3.52 (d, J=6.3 Hz, 2H), 3.99 (s, 2H), 4.34 (m, 2H), 5.14 (s, 2H), 5.32 (m, 1H) ppm.

Workup

  1. customthe reaction was quenched with 1N HCl (0.5 mL)
  2. customThe MeOH was removed in vacuo
  3. customthe crude material was partitioned between DCM and water
  4. extractionThe aqueous layer was extracted with DCM
  5. washthe combined organic layers were washed with sodium bicarbonate solution
  6. dry with materialdried over sodium sulfate
  7. filtrationFiltration and evaporation of solvents
  8. customyielded a crude oil, which
  9. customwas purified by silica
  10. customget chromatography

Sources & evidence

ORD record
ord-96c03bf9e4a945c18f23502f8d21d0d8
Source dataset
uspto-grants-2008_09
Patent number
US07427636B2

Reaction notes

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