Both are dehydrated by refluxing wiih acetic anhydride, the former also being dehydrated by treatment with benzoyl chloride in pyridine. In contrast, VI and VI1 form stable diacetates when refluxed in atetic anhydride, and stable dibenzoates when treated with benzoyl chloride in pyridine. When a diester of I is treated with one equivalent of sodium ethoxidc, u partial conversion to the unesterified parent substatice and to the anhydride, I11 results. ...
![[4-[[3-(2,2-dimethylpropanoyloxy)-2-oxo-chromen-4-yl]methyl]-2-oxo-chr omen-3-yl] 2,2-dimethylpropanoate结构式](https://image.chemsrc.com/caspic/209/81456-57-7.png)