p-Toluenesulfonic acid monohydrate → (1R,6S)- 4,7,7-Trimethyl-3-oxabicyclo[4.1.0]hept-4-en-2-one

HRID 263160Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 263160
[CH3:1][C:2]1([CH3:12])[C@@H:4]([CH2:5][C:6](=O)[CH3:7])[C@H:3]1[C:9]([OH:11])=[O:10].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C(OC(=O)C)(=O)C.C1C=CC=CC=1.CCOCC>[CH3:7][C:6]1[O:10][C:9](=[O:11])[C@@H:3]2[C@H:4]([CH:5]=1)[C:2]2([CH3:12])[CH3:1]

Komponenten

6

Edukt 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 10899111(1R,3S)-2,2-Dimethyl-3-(2-oxopropyl)cyclopropanecarboxylic acid

Produkt 1

HCID 11789393(1R,6S)- 4,7,7-Trimethyl-3-oxabicyclo[4.1.0]hept-4-en-2-oneAusbeute 93 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 241BenzeneLösungsmittelHCID 3283Diethyl EtherLösungsmittelHCID 7918Acetic AnhydrideLösungsmittel

Versuchsvorschrift

A solution of 20 g (0.17 mol) of (1R,cis)-2,2-dimethyl-3-(2-oxopropyl)cyclopropane-1-carboxylic acid and 3 g (0.016 mol) of p-toluenesulfonic acid monohydrate in 93 ml of acetic anhydride and 150 ml of benzene was stirred for 30 minutes at 10°-20° C. The slightly darkened mixture was diluted with ether and washed with ice cold saturated sodium bicarbonate solution until the washings were basic. The organic phase was dried over anhydrous magnesium sulfate and decolorized with charcoal. The solvent was evaporated in vacuo to give 24 g (93%) of the product as a tan solid. Recrystallization from pentane gave a white solid (III) mp 44°-45.5° C., [α]D25 -85.6° (c, 2.0; CHCl3).

Aufarbeitung

  1. washwashed with ice cold saturated sodium bicarbonate solution until the washings
  2. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
  3. customThe solvent was evaporated in vacuo

Quellen und Nachweise

ORD-Eintrag
ord-a8a7b92029f74fb690aa2219bc0239e8
Quelldatensatz
uspto-grants-1979_05
Patentnummer
US04156692

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