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

HRID 32968Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 32968
[CH3:1][O:2][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].[Li+].[BH4-]>CO.C1COCC1>[OH:25][CH2:24][C:23]([CH3:26])=[CH:22][CH2:21][C:4]1[C:5]([O:14][CH2:15][CH2:16][Si:17]([CH3:18])([CH3:20])[CH3:19])=[C:6]2[C:10]([CH2:9][O:8][C:7]2=[O:13])=[C:11]([CH3:12])[C:3]=1[O:2][CH3:1]

Komponenten

5

Edukt 2

HCID 4148881Lithium borohydrideHCID 765461944-[6-Methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-2-methyl-but-2-enal

Produkt 1

HCID 670102606-(4-Hydroxy-3-methyl-but-2-enyl)-5-methoxy-4-methyl-7-(2-trimethylsilanyl-ethoxy)3H-isobenzofuran-1-oneAusbeute 97,8 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 887MethanolLösungsmittelHCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

A solution of 4-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-2-methyl-but-2-enal (103 mg, 0.27 mmol) in methanol (5 mL) was cooled to 0° C. A solution of CeCl3 (0.68 mL, MeOH:H2O, 9:1) was added, followed by LiBH4 (0.14 mL, 0.28 mmol of a 2M solution in THF). The ice bath was removed and the reaction mixture was allowed to warm to room temperature. The reaction mixture was stirred for an additional 40 minutes whereupon TLC indicated complete consumption of starting aldehyde. The reaction was worked up by addition of aqueous 1N HCl (0.5 mL) and the product was extracted with CH2Cl2. The organic layer was washed with saturated aqueous sodium bicarbonate solution and brine. The organic layer was concentrated under reduced pressure and the residue was purified by silica gel chromatography to provide 100 mg (97%) of the product as a clear liquid. 1H NMR (300 MHz, CDCl3) δ 0.00 (s, 9H), 1.20 (dd, 2H, J=7, 8 Hz), 1.81 (s, 3H), 2.13 (s, 3H), 3.38-3.50 (m, 2H), 3.74 (s, 3H), 3.95 (s, 2H), 4.27 (dd, 2H, J=7, 8 Hz), 5.08 (s, 2H), 5.17-5.44 (m, 1H) ppm.

Aufarbeitung

  1. customThe ice bath was removed
  2. customconsumption of starting aldehyde
  3. additionThe reaction was worked up by addition of aqueous 1N HCl (0.5 mL)
  4. extractionthe product was extracted with CH2Cl2
  5. washThe organic layer was washed with saturated aqueous sodium bicarbonate solution and brine
  6. concentrationThe organic layer was concentrated under reduced pressure
  7. customthe residue was purified by silica gel chromatography

Quellen und Nachweise

ORD-Eintrag
ord-9bd95cf0f47e47d7bdf493fc1d9f48ae
Quelldatensatz
uspto-grants-2008_09
Patentnummer
US07427636B2

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