Department of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, USA.
J Am Chem Soc. 2010 Sep 8;132(35):12422-5. doi: 10.1021/ja103916t.
The tandem cyclopropanation/Cope rearrangement between bicyclic dienes and siloxyvinyldiazoacetate, catalyzed by the dirhodium catalyst Rh(2)(R-PTAD)(4), effectively accomplishes enantiodivergent [4 + 3] cycloadditions. The reaction proceeds by a cyclopropanation followed by a Cope rearrangement of the resulting divinylcyclopropane. This methodology was applied to the synthesis of (+)-barekoxide (1) and (-)-barekol (2).
双环二烯与硅氧基乙烯基重氮乙酸酯的串联环丙烷化/Cope 重排反应,在双钌催化剂 Rh(2)(R-PTAD)(4)的催化下,有效地实现了对映体发散的[4 + 3]环加成反应。反应通过环丙烷化反应进行,然后是生成的二乙烯基环丙烷的 Cope 重排。该方法被应用于(+)-barekoxide(1)和(-)-barekol(2)的合成。