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

HRID 1856145Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1856145
[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 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-c2ef7354410f4fdf9b8470d9b39e6faf
Quelldatensatz
uspto-grants-1980_08
Patentnummer
US04218402

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