烯丙醇在Re 2 O 7的存在下进行转座反应,从而可以通过用一种亲电亲和剂捕获一种异构体来控制平衡。当捕获基团是醛或酮时,可能会发生其他电离,从而导致形成环氧碳鎓离子。通过将双分子亲核加成至中间物来终止该过程,为合成各种含氧杂环化合物提供了一种通用的方法。了解序列中各步骤的相对速率会导致设计反应,从而创建多个具有良好至极佳控制水平的立体中心。
Highly stereoselective tandem cyclizations of 5-hexenyllithiums: preparation of endo-2-substituted bicyclo[2.2.1]heptanes and 3-substituted trans-bicyclo[3.3.0]octanes
作者:William F. Bailey、Atmaram D. Khanolkar、Kaustubh V. Gavaskar
DOI:10.1021/ja00047a013
日期:1992.10
diolefinic alkyl iodides by low-temperature lithium-iodine exchange, proceeds via two highly stereoselective and totally regiospecific 5-exo-trig ring closures to deliver bicyclic alkyllithiums. Trapping of the organolithium product by addition of an electrophile cleanly affords functionalized bicyclic molecules in good yield. In this way both endo-2-substituted bicyclo[2.2.1]heptanes and 3-substituted
Heterocycle Synthesis Based on Allylic Alcohol Transposition Using Traceless Trapping Groups
作者:Youwei Xie、Paul E. Floreancig
DOI:10.1002/anie.201402010
日期:2014.5.5
Allylic alcohols undergo transposition reactions in the presence of Re2O7 whereby the equilibrium can be dictated by trapping one isomer with a pendent electrophile. Additional ionization can occur when the trapping group is an aldehyde or ketone, thus leading to cyclic oxocarbenium ion formation. Terminating the process through bimolecular nucleophilic addition into the intermediate provides a versatile
烯丙醇在Re 2 O 7的存在下进行转座反应,从而可以通过用一种亲电亲和剂捕获一种异构体来控制平衡。当捕获基团是醛或酮时,可能会发生其他电离,从而导致形成环氧碳鎓离子。通过将双分子亲核加成至中间物来终止该过程,为合成各种含氧杂环化合物提供了一种通用的方法。了解序列中各步骤的相对速率会导致设计反应,从而创建多个具有良好至极佳控制水平的立体中心。
Cascade Approach to Stereoselective Polycyclic Ether Formation: Epoxides as Trapping Agents in the Transposition of Allylic Alcohols
作者:Youwei Xie、Paul E. Floreancig
DOI:10.1002/anie.201208132
日期:2013.1.7
Complexity from simplicity: Polycyclic ethers are synthesized by cascade reactions involving the use of epoxides as electrophilic traps in the transposition of allylic alcohols. Stereogenic centers are created by functionalizing prochiral sites under thermodynamic control, and remote stereoinduction can be achieved through the use of ketones as conduits.