2,2-Dimethyl-3-(toluene-4-sulfonyloxy)butyric acid methyl ester → 2,2-Dimethyl-3-butenoic acid methyl ester
Reaktionsgleichung
[CH3:1][O:2][C:3](=[O:20])[C:4]([CH3:19])([CH3:18])[CH:5](OS(C1C=CC(C)=CC=1)(=O)=O)[CH3:6]>C1CCN2C(=NCCC2)CC1.CCOCC>[CH3:1][O:2][C:3](=[O:20])[C:4]([CH3:19])([CH3:18])[CH:5]=[CH2:6]Komponenten
4
Versuchsvorschrift
A solution of 2,2-dimethyl-3-(toluene-4-sulfonyloxy)-butyric acid methyl ester (18.06 g, 0.06 mol) in DBU (15 ml) was heated at 140-160° for 3.5 h. The mixture was allowed to cool to room temperature and was then diluted with ether. The mixture was washed with HCl (1 M), sodium bicarbonate, then brine. The ethereal layer was dried and partially evaporated to give a concentrated solution of 2,2-dimethyl-but-3-enoic acid methyl ester (10 g). (Savu and Katzenellenbogen, J. Org. Chem, 46:239-250 (1981)). Further evaporation was avoided due to the volatility of the product (bp 102°). (Tsaconas et al., Aust. J. Chem., 53:435-437 (2000)).