9-(4,4-dimethyl-2-hydroxy-6-oxo-1-cyclohexenyl)-3,3,6,6-tetramethyl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroxanthene

2-丁酮二乙基缩醛

三溴乙烯

3,3-diethoxypentane

octan-2-one-diethylacetal