Abstract：
We report flexible synthesis of new unsymmetrically 2,6-disubstituted benzoquinones (33 examples) and a systematic study of their reactivity in the Diels-Alder reaction. The Diels-Alder reactions of selected unsymmetrical benzoquinones with seemingly similar substituents were found to proceed with high regioselectivity and the formation of selected experimentally observed main products was rationalized by theoretical (DFT) calculations. The findings can be exploited in the convenient preparation of densely substituted and stereochemically defined decalins with unique angular substituents at ring fusion. We also demonstrate the usefulness of this methodology in complex molecule synthesis through the total synthesis of a novel forskolin analog possessing an ethyl group at the fusion of the rings B and C.
摘要：
我们报告了新的不对称2,6-二取代的苯醌的灵活合成（33个实施例），并系统地研究了它们在Diels-Alder反应中的反应性。发现具有看似相似的取代基的选定不对称苯醌的Diels-Alder反应以高区域选择性进行，并且通过理论（DFT）计算合理地形成了选定的实验观察到的主要产物。该发现可用于方便地制备在环融合处具有独特角度取代基的密集取代和立体化学定义的十肽。我们还通过在环B和C的融合处具有乙基的新型毛喉素类似物的全合成，证明了该方法在复杂分子合成中的有用性。
