1,3-Cyclohexanedione → 3,3-Dimethyl-1,5-dioxaspiro[5.5]undecan-8-one
Reaktionsgleichung
[C:1]1(=[O:8])[CH2:6][CH2:5][CH2:4][C:3](=[O:7])[CH2:2]1.[CH3:9][C:10]([CH3:15])([CH2:13]O)[CH2:11][OH:12]>C1(C)C=CC=CC=1>[CH3:9][C:10]1([CH3:15])[CH2:11][O:12][C:3]2([CH2:4][CH2:5][CH2:6][C:1](=[O:8])[CH2:2]2)[O:7][CH2:13]1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
125 g (630 mmole) 3,3-dimethyl-1,5-dioxa-spiro[5,5]undecan-8-one, which was obtained by the azeotropic acetylation of cyclohexane-1,3-dione with 2,2-dimethylpropane-1,3-diol in toluene as a solvent using p-toluenesulphonic acid as a catalyst, and 59 g (630 mmole) dimethylammonium methylene chloride were stirred at room temperature in 400 ml of dry acetonitrile. After adding 1 ml acetyl chloride the mixture was stirred for a further 3 hours at room temperature, whereupon a clear colourless solution was obtained. 800 ml of dry ether were then added drop-wise to the reaction mixture, whereupon the hydrochloride crystallised out. 158 g of (18) were obtained (98% theoretical).