Preparation of Polyacetoxytropones and Polyhydroxytropolones by Acetolysis and Hydrolysis of Halotroponoids by Acetyl Trifluoroacetate with Exhaustive Displacement of Halogens on the Tropone Ring. Predominant Formation of Reductive Acetolysates from Fully-Substituted Tropones
作者:Hitoshi Takeshita、Akira Mori、Tomoyuki Kusaba、Hiroyasu Watanabe
DOI:10.1246/bcsj.60.4325
日期:1987.12
acetic acid-mediated reduction of intermediary formed acetoxy-p-tropoquinone equivalents. A couple of 2,7-unsubstituted 3,4-diacetoxytropones were deduced to have cyclized 1,3-dioxole structures, 2-acetoxy-2-methyl-5H-cyclohepta-1,3-dioxol-5-ones. An acetolysis of the brominated 5-isopropyltropolones furnished an acetylated by-product, 2,3,7-triacetoxy-5-(1,1-dimethyl-2-oxopropyl)tropone, which might be
通过将相应的卤代托品酮或多卤代托品酮与乙酰基三氟乙酸酯进行乙酰水解,然后进行乙酸水解,可以高产率地制备二、三和四羟基托品酮。然而,使用相同的处理获得具有完全取代的乙酰氧基卤代酮的六乙酰氧托酮主要产生比预期更少的取代乙酰氧托酮;已证明形成机制涉及乙酸介导的中间形成的乙酰氧基-对-原苯醌等效物的还原。一些 2,7-未取代的 3,4-diacetoxytropones 被推导出具有环化的 1,3-dioxole 结构,2-acetoxy-2-methyl-5H-cyclohepta-1,3-dioxol-5-ones。溴化 5-异丙基托酚酮的乙酰化提供乙酰化副产物 2,3,7-三乙酰氧基-5-(1,1-二甲基-2-氧代丙基)托酮,