Cationic Cyclization of 2-Alkenyl-1,3-dithiolanes: Diastereoselective Synthesis of <i>trans</i>-Decalins
作者:Sylvie Goncalves、Stefano Santoro、Marc Nicolas、Alain Wagner、Philippe Maillos、Fahmi Himo、Rachid Baati
DOI:10.1021/jo2001116
日期:2011.5.6
TMSOTf, triggering the cationic 6-endo-trig cyclization, and closes after C−C bond formation and diastereoselective protonation to terminate the process. DFT calculations confirm this mechanistic proposal and provide a rationale for the observed diastereoselectivity. The reaction tolerates a wide range of functionalities and nucleophilic partners within the substrate. We have also shown that the one-pot
前所未有的和高度非对映6-内-三角函数的2-链烯基-1,3-二硫戊环化已经发展得到反式-decalins,存在于众多的二-和三萜类化合物的一个重要的支架。这个6-的新颖性内切- trig的环化手段在涉及2-链烯基-1,3-二硫戊环的分步机构,作为一个新的潜引发剂。有人建议,在硫缩酮暂时打开将TMSOTf的影响下,引发阳离子6-内- TRIG环化,并在C-C键形成和非对映选择性质子化后关闭,以终止该过程。DFT计算证实了这一机理性建议,并为观察到的非对映选择性提供了理论依据。该反应可耐受底物内的多种功能和亲核伴侣。我们还表明,一锅煮6-内- trig的环化,随后在原位1,3-二硫戊直接脱保护得到相应的酮。这一改进使得雷公藤多酚的总合成最短,雷公藤内酯的形式最短。