[F:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6]([CH3:13])([CH3:12])[CH2:7][C:8]2=[O:11])=[CH:4][CH:3]=1.[CH3:14][CH:15](O)[CH:16]=[CH2:17].C1(C)C=CC(S(O)(=O)=O)=CC=1.O>COC(OC)(C)C>[CH2:14]([CH:7]1[C:6]([CH3:13])([CH3:12])[C:5]2[C:9](=[CH:10][C:2]([F:1])=[CH:3][CH:4]=2)[C:8]1=[O:11])[CH:15]=[CH:16][CH3:17]A solution of 10.0 g of 6-fluoro-3,3-dimethyl-1-indanone, 11.1 ml of 3-buten-2-ol and 200 mg of p-toluenesulfonic acid in 200 ml of 2,2-dimethoxypropane was boiled under reflux for 96 hours on a water separator filled with molecular sieve (0.4 nm, 2 mm pearl shaped). The reaction mixture was subsequently concentrated in a vacuum and purified by column chromatography on silica gel (hexane/ethyl acetate 8:1). In addition to 11.9 g of educt, there were obtained 3.38 g (26%) of (RS)-2-(2-buten-1-yl)-6-fluoro-3,3-dimethyl-1-indanone as a yellow oil.
Wird geladen…