Dimethyl Sulfate → (S)-(+)-2-ethynyl-3,4-dihydro-6-methoxy-2,5,7,8-tetramethyl-2H-1-benzopyran

HRID 1199194

Reaktionsgleichung

Reaktionsgleichung von HRID 1199194
[C:1]([C@:3]1([CH3:17])[CH2:8][CH2:7][C:6]2[C:9]([CH3:16])=[C:10]([OH:15])[C:11]([CH3:14])=[C:12]([CH3:13])[C:5]=2[O:4]1)#[CH:2].S(OC)(O[CH3:22])(=O)=O.[OH-].[Na+].[OH-].[NH4+]>CC(C)=O>[C:1]([C@:3]1([CH3:17])[CH2:8][CH2:7][C:6]2[C:9]([CH3:16])=[C:10]([O:15][CH3:22])[C:11]([CH3:14])=[C:12]([CH3:13])[C:5]=2[O:4]1)#[CH:2]

Komponenten

6

Edukt 4

HCID 6497Dimethyl SulfateHCID 14798Sodium HydroxideHCID 14923Ammonium HydroxideHCID 9859440(S)-2-ethynyl-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol

Produkt 1

HCID 14478580(S)-(+)-2-ethynyl-3,4-dihydro-6-methoxy-2,5,7,8-tetramethyl-2H-1-benzopyranAusbeute 47 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 180AcetoneLösungsmittel

Versuchsvorschrift

A solution of (S)-(+)-2-ethynyl-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol (354 mg, 1.54 mmol) in acetone (9 mL) was treated with dimethyl sulfate (0.8 mL), and 50% NaOH (1.2 mL) for 2 h at 25° C. with stirring. Ammonium hydroxide solution (1.0N, 50 mL) was added, and it was extracted with ether (3×50 mL). The extracts were combined, washed with 1.0 N HCl, water, and dried over MgSO4. It was filtered and concentrated in vacuo to give 400 mg of solid, which or crystallization from ether-hexane (1:12) afforded 141 mg (47%) of (S)-(+)-2-ethynyl-3,4-dihydro-6-methoxy-2,5,7,8-tetramethyl-2H-1-benzopyran as white prisms : mp 94°-97° C., [α]D25 +53.86°, (C 0.4233, CHCl3).

Aufarbeitung

  1. extractionit was extracted with ether (3×50 mL)
  2. washwashed with 1.0 N HCl, water
  3. dry with materialdried over MgSO4
  4. filtrationIt was filtered
  5. concentrationconcentrated in vacuo
  6. customto give
  7. custom400 mg of solid, which or crystallization from ether-hexane (1:12)

Quellen und Nachweise

ORD-Eintrag
ord-92c4b1dde8eb40feac26d1056ef7c7a1
Quelldatensatz
uspto-grants-1990_02
Patentnummer
US04898953

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