76593-72-1Relevant academic research and scientific papers
ENAMINE CHEMISTRY XX. SYNTHESIS OF FURAN DERIVATIVES BY REDUCTIVE CYCLISATION OF ENAMINES
Carlsson, S.,El-Barbary, A. A.,Lawesson, S.-O.
, p. 643 - 650 (2007/10/02)
Enamines, I, prepared from cyclohexanones or cyclopentanones and pyrrolidine are alkylated with 2-bromoesters (ethyl 2-bromoethanoate, ethyl 2-bromopropanoate, methyl 2-bromopropanoate) to give new enamines, II, which after treatment with LiAlH4 undergo reductive cyclisation reactions giving the furan derivatives, III (7a-pyrrolidino-octahydrobenzofurans, 6a-pyrrolidino-hexahydrocyclopentafurans) in almost quantitative yields.The compounds III are hydrolyzed with hydrochloric acid to octahydrobenzofuran-7a-ols or hexahydrocyclopentafuran-6a-ols, IV.Elimination of pyrrolidine from III with oxalic acid in anhydrous dioxane yields condensed dihydrofurans, V.
