Water → (R)-(-)-3,4-Dihydro-2-(4-methoxybenzyl)-2H-benzopyran

HRID 2253969

Reaktionsgleichung

Reaktionsgleichung von HRID 2253969
FC(F)(F)S(O[CH2:7][C@H:8]1[CH2:13][CH2:12][C:11]2[CH:14]=[CH:15][CH:16]=[CH:17][C:10]=2[O:9]1)(=O)=O.C([Mg]Br)[C:21]1[CH:26]=[CH:25][C:24]([O:27][CH3:28])=[CH:23][CH:22]=1.O.[Cl-].[NH4+]>O1CCCC1.C(Cl)Cl>[CH3:28][O:27][C:24]1[CH:25]=[CH:26][C:21]([CH2:7][C@H:8]2[CH2:13][CH2:12][C:11]3[CH:14]=[CH:15][CH:16]=[CH:17][C:10]=3[O:9]2)=[CH:22][CH:23]=1

Komponenten

7

Edukt 4

HCID 962WaterHCID 25517Ammonium ChlorideHCID 15740458(R)-(-)-3,4-Dihydro-2-trifluoromethanesulfonyloxymethyl-2H-benzopyranHCID 178418276HCID 178418276, Verbindung

Produkt 1

HCID 18653186(R)-(-)-3,4-Dihydro-2-(4-methoxybenzyl)-2H-benzopyranAusbeute 92 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 6344DichloromethaneLösungsmittelHCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
-10 °C

Versuchsvorschrift

(R)-(-)-3,4-Dihydro-2-trifluoromethane-sulfonyloxymethyl-2H-benzopyran(23.0 g, 78 mmol) and copper (I) bromide dimethyl sulfide complex (2.8 g, 12 mmol) were dissolved in tetrahydrofuran (400 ml) under a nitrogen atmosphere and cooled to -10° C. 4-Anisylmagnesium bromide (215 ml of a 1M solution in tetrahydrofuran, 0.215 mol) was added dropwise over 30 minutes, keeping the temperature below -5° C. The solution was stirred for 3 hours at 0° C. and then slowly poured into a mixture of water (800 ml) containing ammonium chloride (96 g, 1.8 mol) and methylene chloride (400 ml). The layers were separated and the aqueous portion was extracted with methylene chloride (400 ml). The combined organics were washed with 10% ammonium chloride (2×400 ml), water (250 ml), and brine (250 ml). The methylene chloride layer was dried (MgSO4), filtered and concentrated in vacuo. The residue was purified on silica gel using hexanes/methylene chloride (1:1 as eluent to afford 18.5 g (92% yield of the title product as an oil. [α]D -99.2° (c 1.7, MeOH); 1H NMR (300 MHz, CLCl3) δ1.6-1.7 (m, 1H), 1.9-2.0 (m, 1H), 2.7-2.8 (m, 3H), 3.1 (dd, 1H), 3.8 (s, 3H), 4.1 (m, 1H), 6.8 (m, 3H), 7.0 (m, 2H), 7.2 (m, 2H).

Aufarbeitung

  1. customthe temperature below -5° C
  2. customThe layers were separated
  3. extractionthe aqueous portion was extracted with methylene chloride (400 ml)
  4. washThe combined organics were washed with 10% ammonium chloride (2×400 ml), water (250 ml), and brine (250 ml)
  5. dry with materialThe methylene chloride layer was dried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified on silica gel

Quellen und Nachweise

ORD-Eintrag
ord-08e1dd6446be4951bbd2f023e04a74fb
Quelldatensatz
uspto-grants-1993_08
Patentnummer
US05232945

Verknüpfte Notizen

Wird geladen…