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

HRID 33671Notes

Reaction equation

HRID 33671 reaction equation
[CH2:1]([C:3](=[CH:6][CH2:7][C:8]1[C:9]([O:21][CH2:22][CH2:23][Si:24]([CH3:27])([CH3:26])[CH3:25])=[C:10]2[C:14](=[C:15]([CH3:19])[C:16]=1[CH2:17][CH3:18])[CH2:13][O:12][C:11]2=[O:20])[CH:4]=[O:5])[CH3:2].[BH4-].[Li+]>CO.CO.O.C1COCC1>[CH2:17]([C:16]1[C:15]([CH3:19])=[C:14]2[C:10](=[C:9]([O:21][CH2:22][CH2:23][Si:24]([CH3:25])([CH3:26])[CH3:27])[C:8]=1[CH2:7][CH:6]=[C:3]([CH2:4][OH:5])[CH2:1][CH3:2])[C:11](=[O:20])[O:12][CH2:13]2)[CH3:18]

Participants

6

Reactant 2

HCID 4148881Lithium borohydrideHCID 765410332-Ethyl-4-[6-ethyl-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-but-2-enal

Product 1

HCID 670102685-Ethyl-6-(3-hydroxymethyl-pent-2-enyl)4-methyl-7-(2-trimethylsilanyl-ethoxy)-3H-isobenzofuran-1-oneYield 70.3%

Reagents, catalysts & solvents 3

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

Conditions

Temperature
0 °C

Procedure

2-Ethyl-4-[6-ethyl-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-but-2-enal (50.3 mg, 0.129 mmol) was dissolved in MeOH (3 mL). A solution of CeCl3 (31.9 mg, 0.129 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, 0.065 mL) was added dropwise. After 10 minutes, the reaction was quenched with 1N HCl (0.5 mL). The methanol 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 were dried over sodium sulfate. Filtration and evaporation of solvents in vacuo yielded a crude oil, which was purified by silica gel chromatography to provide 35.4 mg (70%) of the desired product. 1H NMR (300 MHz, CDCl3): δ=0.04 (s, 9H), 1.10-1.19 (m, 6H), 1.26 (m, 2H), 2.19 (s, 3H), 2.32 (q, J=7.5 Hz, 2H), 2.72 (q, J=7.5 Hz, 2H), 3.54 (d, J=6.6 Hz, 2H), 4.05 (s, 2H), 4.26 (m, 2H), 5.14 (s, 2H), 5.27 (m, 1H) ppm.

Workup

  1. customthe reaction was quenched with 1N HCl (0.5 mL)
  2. customThe methanol 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 materialwere dried over sodium sulfate
  7. filtrationFiltration and evaporation of solvents in vacuo
  8. customyielded a crude oil, which
  9. customwas purified by silica gel chromatography

Sources & evidence

ORD record
ord-2cba54d67d854c28bbf0441945229d32
Source dataset
uspto-grants-2008_09
Patent number
US07429565B2

Reaction notes

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