In this report, a general method for the preparation of 1,5-dicarbonyl compounds and six membered ring annelation is described. This method involves the reaction of hemiacetal vinylogs 1 with enol ethers 2 or 3 in the presence of a Lewis acid. This reaction was successfully applied to the enol ethers of α and α,α'-hindered ketones such as 2,2,6-trimethyl cyclohexanone. α-Cyperone and 6-epi-α-cyperone were obtained using this process.

中文翻译：

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1,5-二羰基化合物：一般制备方法

在此报告中，描述了制备1,5-二羰基化合物和六元环成环的一般方法。该方法涉及在路易斯酸存在下半缩醛乙烯基酯1与烯醇醚2或3的反应。该反应成功地应用于α和α，α'受阻的酮的烯醇醚，例如2,2,6-三甲基环己酮。使用该方法获得α-Cyperone和6-epi-α-Cyperone。