[CH2:1]([O:8][CH2:9][CH2:10][CH:11]1[CH2:20][CH2:19][C:14]2(OCC[O:15]2)[CH2:13][CH2:12]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O.CC1C=CC(S(O)(=O)=O)=CC=1>CC(C)=O>[CH2:1]([O:8][CH2:9][CH2:10][CH:11]1[CH2:12][CH2:13][C:14](=[O:15])[CH2:19][CH2:20]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=18-(2-Benzyloxy-ethyl)-1,4-dioxa-spiro[4.5]decane (Intermediate A1) (1.02 g, 3.70 mmol) (obtained as described in: Ciufolini et. al. J. Amer. Chem. Soc. 1991, 113, 8016, incorporated herein by reference) was dissolved in acetone (100 mL):H2O (5 mL) and reacted with TsOH (140 mg, 0.74 mmol) at 45° C. for 5 h. After a standard aqueous work-up the material was purified by chromatography on SiO2 to give 4-(2-benzyloxy-ethyl)-cyclohexanone as a colorless oil (97%).
Wird geladen…
