Br.C(OC([C:7]1([CH2:13][C:14]2[CH:19]=[CH:18][C:17]([CH2:20][C:21]([O:23]CC)=[O:22])=[CH:16][CH:15]=2)[CH2:11][CH2:10][CH2:9][C:8]1=[O:12])=O)C>O1CCOCC1>[O:12]=[C:8]1[CH2:9][CH2:10][CH2:11][CH:7]1[CH2:13][C:14]1[CH:15]=[CH:16][C:17]([CH2:20][C:21]([OH:23])=[O:22])=[CH:18][CH:19]=1Into a mixture of 20 ml of 47% hydrobromic acid and 15 ml of dioxane was dissolved 9.2 g of ethyl 4-(1-ethoxycarbonyl-2-oxocyclopentan-1-ylmethyl)phenylacetate and the solution was refluxed for 6 hours. The solvent was then removed by distillation from the reaction mixture, the residue was poured into ice-water and extracted with ether. The extract was washed with water, dried over anhydrous sodium sulfate, the solvent removed by distillation to give an oily substance, which was subjected to a vacuum distillation to yield 6.0 g of an oily product, b.p. 185°-195° C. at 0.7 mm Hg (bath temp.).
Wird geladen…