Department of Chemistry , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599-3290 , United States.
Org Lett. 2019 Aug 16;21(16):6504-6507. doi: 10.1021/acs.orglett.9b02372. Epub 2019 Jul 30.
Phenols are attractive starting materials for the preparation of highly substituted cyclohexane rings via dearomative processes. Herein we report an efficient preparation of dearomatized 1-oxaspiro[2.5]octa-4,7-dien-6-ones (-spiroepoxydienones) via the nucleophilic epoxidation of in situ generated -quinone methides from 4-(hydroxymethyl)phenols using aqueous HO. The developed protocol bypasses the need for stoichiometric bismuth reagents or diazomethane, which are frequently deployed for spiroepoxydienone preparation. The -spiroepoxydienones are further elaborated in numerous downstream complexity-building transformations.
酚类化合物是通过去芳构化过程制备高度取代环己烷环的有吸引力的起始材料。在此，我们报告了一种通过亲核环氧化原位生成的 - 醌甲醚，从 4-（羟甲基）苯酚中高效制备去芳构化的 1-氧杂螺[2.5]辛-4,7-二烯-6-酮（-螺环氧二烯酮）的方法，使用水性 HO。所开发的方案避免了使用经常用于螺环氧二烯酮制备的化学计量双试剂或重氮甲烷的需要。-螺环氧二烯酮进一步在许多下游的复杂性构建转化中得到了详细阐述。
