Мова оригіналу: Англійська
The reaction of ethyl 2-oxocyclopentanecarboxylate (I) with ethyl 2-(4-chloromethylphenyl)propionate
(II) by means of KOH in hot DMF gives ethyl 2-[4-(1-ethoxycarbonyl-2-oxocyclopentan-1-ylmethyl)phenyl]propionate
(III), which is then hydrolyzed anddecarboxylated by treatment with 47% HBr in refluxing dioxane