四丁基碘化铵催化合成螺[4.4]壬烷-1,6-二酮

Synthesis of Spir[4.4]ononane-1,6-dione Catalyzed by Tetrabutylammonium Iodide

改进了螺[4.4]壬烷-1,6-二酮的合成方法。以环戊酮-2-羧酸乙酯和4-溴丁酸乙酯为起始原料、四丁基碘化铵为催化剂、THF为溶剂、碳酸钾为碱,制备了4-(1-乙氧羰基-2-氧代环戊基)丁酸乙酯,产率达到87%。该反应条件温和,不需要在无水无氧条件下进行。4-(1-乙氧羰基-2-氧代环戊基)丁酸乙酯经水解脱羧和关环反应得到外消旋螺[4.4]壬烷-1,6-二酮。

Ethyl 4-（1-ethoxycarbonyl-2-oxocyclopentyl）butanoate was prepared successfully from ethyl 2-oxocyclopentanecarboxylate and ethyl 4-bromobutanoate catalyzed by tetrabutylammonium iodide under mild conditions,with THF as solvent and K2CO3 as base.Spirononane-1,6-dione was synthesized by hydrolysis and decarboxylation of ethyl 4-（1-ethoxycarbonyl-2-oxocyclopentyl）butanoate followed by ring closure reaction.