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).
双环二烯和
硅氧基
乙烯基重氮乙酸酯之间的串联
环丙烷化/Cope 重排,由二
铑催化剂 Rh(2)(R-
PTAD)(4) 催化,有效地实现了对映发散 [4 + 3] 环加成。该反应通过
环丙烷化和所得二
乙烯基环丙烷的Cope重排进行。该方法用于合成 (+)-barekoxide (1) 和 (-)-barekol (2)。