Dialkoxycarbenes are more reactive than NHCs and participate in many reactions including a formal (4 + 1) cycloaddition with electron-deficient dienes. We have learned to control the relative stereochemistry of the newly created chiral carbons in this process and now report that, combined with a chiral auxiliary, it has been used successfully in a short and efficient synthesis of the sesquiterpene
二烷氧碳烯比NHC更具反应性,并且参与许多反应,包括与电子不足的二烯进行的正式(4 +1)环加成反应。我们已经学会了在此过程中控制新创建的手性碳的相对立体
化学,现在报道,与手性助剂结合使用,已成功地用于
倍半萜烯
胡萝卜素的短而有效的合成中。