Reaktion #574810

ord-a89a39ed35484a80bb1e92a62f3e07b5

Reaktionsgleichung

CC(=O)O[C@H]1[C@H](n2ccc(CO[Si](C)(C)C(C)(C)C)cc2=O)c2cc(C#N)ccc2OC1(C)C
trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxy-1-pyridinyl)-2H-benzo[b]pyran
CC(=O)O[C@H]1[C@H](n2ccc(CO[Si](C)(C)C(C)(C)C)cc2=O)c2cc(C#N)ccc2OC1(C)C
trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran
Cl
hydrochloric acid
→
CC(=O)O[C@H]1[C@H](n2ccc(CO)cc2=O)c2cc(C#N)ccc2OC1(C)C
trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-hydroxymethyl-1-pyridinyl)-2H-benzo[b]pyran
Ausbeute 95.8%

Edukte

CC(=O)O[C@H]1[C@H](n2ccc(CO[Si](C)(C)C(C)(C)C)cc2=O)c2cc(C#N)ccc2OC1(C)C
trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxy-1-pyridinyl)-2H-benzo[b]pyran
CC(=O)O[C@H]1[C@H](n2ccc(CO[Si](C)(C)C(C)(C)C)cc2=O)c2cc(C#N)ccc2OC1(C)C
trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxymethyl-1-pyridinyl)-2H-benzo[b]pyran
Cl
hydrochloric acid

Reagenzien

Keine

Lösungsmittel

CO
methanol
C1COCCO1
dioxane

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    Sonstigeat 0° C. and reacted at room temperature for 2 hours
  2. 2
    EinengenThe reaction mixture is concentrated under reduced pressure
  3. 3
    workup.ADDITIONthe residue is mixed with water and ethyl acetate
  4. 4
    Extraktionthe product is extracted by ethyl acetate
  5. 5
    WaschenThe organic layer is washed with saturated aqueous solution of sodium chloride
  6. 6
    Trocknendried over anhydrous sodium sulfate
  7. 7
    FiltrationThen, the inorganic matter is filtered off
  8. 8
    Einengenthe filtrate is concentrated under reduced pressure
  9. 9
    SonstigeThe residue is purified by silica gel column chromatography

Vorschrift

In 15.0 ml of methanol, is dissolved 1.45 g of trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxy-1-pyridinyl)-2H-benzo[b]pyran obtained in Example 4. Then, 3.00 ml of 4N hydrochloric acid in dioxane is added thereto at 0° C. and reacted at room temperature for 2 hours. The reaction mixture is concentrated under reduced pressure, the residue is mixed with water and ethyl acetate, and the product is extracted by ethyl acetate. The organic layer is washed with saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. Then, the inorganic matter is filtered off and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using ethyl acetate as a developing solvent to obtain 1.06 g of trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-hydroxymethyl-1-pyridinyl)-2H-benzo[b]pyran.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US05296492uspto-grants-1994_03