A Pummerer-based generation and trapping of furo[3,4- c ]pyridines: an approach to nitrogen containing heterocyclic analogues of 1-arylnaphthalene lignans
作者:Tarun K Sarkar、Sankar Basak、Niranjan Panda
DOI:10.1016/s0040-4039(01)02379-6
日期:2002.2
the neighbouring keto functionality produces thio-substituted furo[3,4-c]pyridines as transient intermediates; the latter undergo [4+2] cycloaddition with an added dienophile. Base-induced ring opening of the cycloadducts followed by aromatization gives substituted isoquinolines related to heterocyclicanalogues of 1-arylnaphthalenelignans.
邻苯甲酰基取代的吡啶基甲基亚砜的Pummerer反应产生α-硫代碳酸盐,邻位酮官能团的拦截产生硫代基的呋喃[3,4- c ]吡啶,作为过渡中间体。后者进行了[4 + 2]环加成反应,并加入了亲二烯体。碱诱导的环加合物的开环,然后进行芳构化,得到与1-芳基萘木酚素的杂环类似物有关的取代异喹啉。
A Sequential Pummerer−Diels−Alder Route for the Generation and Trapping of Furo[3,4-<i>c</i>]pyridines: Synthesis of Heterocyclic Analogues of 1-Arylnaphthalene Lignans
作者:Tarun K. Sarkar、Niranjan Panda、Sankar Basak
DOI:10.1021/jo0344081
日期:2003.9.1
looked upon as a heterocyclicanalogue of 1-arylnaphthalene lignans. This procedure occurs readily with electron-poor dienophiles and the entire sequence can be run in one pot. The facility of the sequential Pummerer-Diels-Alder reaction hinges on the experimental conditions, the best results being obtained with heptafluorobutyric anhydride as the triggering agent in toluene containing a catalytic amount