4-Formyl-bicyclo[3.2.1]octane-1-carboxylic acid ethyl ester → Bicyclo[3.2.1]octane-1,4-dicarboxylic acid 1-ethyl ester
Reaktionsgleichung
[CH2:1]([O:3][C:4]([C:6]12[CH2:13][CH:10]([CH2:11][CH2:12]1)[CH:9]([CH:14]=[O:15])[CH2:8][CH2:7]2)=[O:5])[CH3:2].CC(C)=[O:18].OS(O)(=O)=O.O=[Cr](=O)=O>>[CH2:1]([O:3][C:4]([C:6]12[CH2:13][CH:10]([CH2:11][CH2:12]1)[CH:9]([C:14]([OH:18])=[O:15])[CH2:8][CH2:7]2)=[O:5])[CH3:2]Komponenten
3
Versuchsvorschrift
To an ice-cold solution of 4-formyl-bicyclo[3.2.1]octane-1-carboxylic acid ethyl ester (3.85 mmol, 0.81 g) was added slowly Jones reagent (2.7 M, 1.43 mL). The reaction was stirred at ice temperature 20 min, then quenched by addition of iPrOH. diluted with H2O and extracted with Et2O (3×). The combined organic extracts were washed with H2O (2×), brine (1×), and dried (MgSO4). Filtration and evaporation provided the viscous oily bicyclo[3.2.1]octane-1,4-dicarboxylic acid 1-ethyl ester (0.76 g, 87%) as a mixture of axial and equatorial acids. 13C NMR (100 MHz, CDCl3): 14.16 (q), 19.86 (t), 21.07 (t), 25.98 (t), 29.20 (t), 31.52 (t), 31.87 (t), 32.27 (t), 33.39 (t), 37.80 (d), 38.07 (t), 38.10 (d), 42.06 (t), 44.80 (d), 45.78 (d), 49.38 (s), 49.60 (s), 60.31 (t), 60.36 (t), 177.08 (s), 180.01 (s).