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| Section3 = }} Cyclobutanone is an organic compound with molecular formula C4H6O. It is a four-membered cyclic ketone (cycloalkanone). Unlike cyclopropanone, the smallest but extremely volatile cyclic ketone, cyclobutanone is a stable liquid at room temperature and can be distilled. ==Preparation== The Russian chemist Nikolai Kischner first reported the preparation of cyclobutanone in 1905. He synthesized cyclobutanone in a low yield from cyclobutanecarboxylic acid in several reaction steps. This process is cumbersome and inefficient by today's standards. : More efficient, high-yielding syntheses have since been developed. One strategy involves degradation of five-carbon building blocks. For example, the oxidative decarboxylation of cyclobutanecarboxylic acid was improved by the use of other reagents and methods. A newer, more efficient preparation of cyclobutanone was found by P. Lipp and R. Köster in which a solution of diazomethane in diethyl ether is reacted with ketene. This reaction is based on a ring expansion of the cyclopropanone intermediate initially formed, wherein molecular nitrogen is split off. The reaction mechanism was confirmed by a reaction using 14C-labeled diazomethane. : Another method for the synthesis of cyclobutanone is through a lithium-catalyzed rearrangement of oxaspiropentane, which is formed by epoxidation of the easily accessible methylenecyclopropane. : Cyclobutanone can also be prepared in a two step procedure by dialkylation of 1,3-dithiane with 1-bromo-3-chloropropane followed by deprotection to the ketone with mercuric chloride (HgCl2) and cadmium carbonate (CdCO3). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyclobutanone」の詳細全文を読む スポンサード リンク
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