Hexose sugars undergo smooth coupling with 1,3-diketones and β-keto esters in the presence of 10 mol% of indium(III) chloride in water at 80 °C to furnish C-furyl glycosides in excellent yields, whereas pentose sugars produce trihydroxyalkyl-substituted furan derivatives with high selectivity. The reactions of cyclic ketones such as cyclohexane-1,3-dione or dimedone with D-glucose in acetonitrile at
己糖与 1,3-二酮和 β-酮酯在 10 mol% 氯化铟 (III) 的水中在 80 °C 存在下平滑偶联,以极好的产率提供 C-呋喃糖苷,而戊糖产生三羟基烷基-取代的呋喃衍生物具有高选择性。环己烷-1,3-二酮或二甲酮等环状酮与 D-葡萄糖在乙腈中于 80 °C 反应生成相应的四氢苯并呋喃糖苷衍生物。
Iron(III) Chloride in Ethanol-Water: Highly Efficient Catalytic System for the Synthesis of Garcia Gonzalez Polyhydroxyalkyl- and C-Glycosylfurans
An efficient method has been developed for the synthesis of Garcia Gonzalez polyhydroxyalkyl- and C-glycosylfurans in excellent yields from unprotected sugar aldoses with β-keto esters by Knoevenagel condensation in the presence of anhydrous iron(III) chloride. d-glucose - β-keto esters - Knoevenagel reaction - furans - carbohydrates