bromomethylation of the side-chain of 2'-acetoxychalcones were found to produce minor quantities of flavones as well as the major product aurones when cyclized by aqueous ethanolic sodium hydroxide. The yields of flavone increased with increasing base concentration. The optimum concentration of hydroxide for aurone formation was below 1%. Greatly diminished yields of O-heterocycles were obtained when a nitro substituent
                                    发现当被氢氧化
乙醇水溶液环化时,通过2'-乙酰氧基
查耳酮的侧链的
溴甲基化形成的
二氢查耳酮产生少量的
黄酮以及主要的产品
金酮。
黄酮类化合物的产率随碱浓度的增加而增加。用于形成
金酮的氢氧化物的最佳浓度低于1%。当在环化2'-氧官能团的对面引入硝基取代基时,会大大降低O-杂环的收率。