Acetone → (2R)-3,4-Dihydro-2H-1-benzopyran-2-methanol

HRID 2298795Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2298795
[C:1]1([CH3:7])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH2:8]([OH:10])[CH3:9].[BH4-].[Na+].Cl.C[C:15](=[O:17])C>O>[O:10]1[C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=2[CH2:7][CH2:9][C@@H:8]1[CH2:15][OH:17]

Komponenten

7

Edukt 5

HCID 180AcetoneHCID 313Hydrochloric AcidHCID 702EthanolHCID 1140TolueneHCID 4311764Sodium borohydride

Produkt 1

HCID 7170029(2R)-3,4-Dihydro-2H-1-benzopyran-2-methanol

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Reaktionsbedingungen

Temperatur
50 °C

Versuchsvorschrift

A mixture of toluene (1000 ml) and ethanol (absolute, 520 ml) was stirred. Sodium borohydride (2.13 mol) was added at room temperature, under an inert atmosphere. The mixture was heated to 50° C. Intermediate (2) (2.14 mol) was added dropwise at 50° C. in a 90-minutes period (exothermic temperature rise of 15° C., cooling required). The reaction mixture was stirred for 90 minutes at 50° C. Water (1500 ml) was added while stirring. Then, 2-propanone (100 ml) was added dropwise under slight cooling. The mixture was decomposed with HCl (180 ml). The organic layer was separated, dried, filtered and the solvent evaporated, yielding 295 g of (−)-(R)-3,4-dihydro-2H-1-benzopyran-2-methanol (interm. 3).

Aufarbeitung

  1. temperature(exothermic temperature rise of 15° C., cooling required)
  2. stirringThe reaction mixture was stirred for 90 minutes at 50° C
  3. stirringwhile stirring
  4. customThe organic layer was separated
  5. customdried
  6. filtrationfiltered
  7. customthe solvent evaporated

Quellen und Nachweise

ORD-Eintrag
ord-c42d060e720b4f0ea545d928174ded52
Quelldatensatz
uspto-grants-2002_12
Patentnummer
US06495547B1

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