Synthesis of Cyclohexenols and Cycloheptenols via the Regioselective Reductive Ring Opening of Oxabicyclic Compounds
作者:Mark Lautens、Shihong Ma、Pauline Chiu
DOI:10.1021/ja964361j
日期:1997.7.1
The reductive ring opening of oxabicyclic compounds has been achieved. While RMgBr/MgBr2 works in a few limited substrates, diisobutylaluminum hydride reacts with oxabicyclic[3.2.1]- and -[2.2.1]alkenes to provide cycloheptenols and cyclohexenols in good yield and in some cases in good regioselectivity. With some substrates further reduction of the alkene was observed which led us to examine transition
已经实现了氧杂双环化合物的还原开环。虽然 RMgBr/MgBr2 在少数有限的底物中起作用,但二异丁基氢化铝与氧杂双环 [3.2.1]- 和 -[2.2.1] 烯烃反应以良好的收率提供环庚烯醇和环己烯醇,在某些情况下具有良好的区域选择性。对于某些底物,观察到烯烃的进一步还原,这使我们研究了已知会加速加氢铝化反应的过渡金属,例如镍。与 Ni(COD)2(COD = 环辛二烯)的反应给出了最佳的反应性 - 选择性曲线,并且在烯烃过度还原最小的情况下获得了显着更高的产率。膦配体显示出显着提高桥头取代的氧杂双环化合物开环的区域选择性。最好的配体是1,4-双(二苯基膦基)丁烷的选择性高达 380:1。一系列的氘淬灭实验表明,氢氧化铝的选择性根据...