Heating of dialkyl- or diarylcyclopropenones at 75 ËC in the presence of copper(I) bromide (5 mol%) affords the corresponding 4-oxaspiro[2.4]hepta-1,6-dien-5-ones in good yields.
在
溴化铜(I)(5 摩尔%)存在下,在 75 ËC下加热二烷基或二芳基
环丙烯酮,可以得到相应的 4-氧杂螺[2.4]庚-1,6-二烯-5-酮,收率很高。