The regioselective [2,3]Wittig rearrangement of bis-allylic ethers followed by the Claisen rearragement permits ready access to (E,E)-4,7-alkadienals and -alkadienoic acids. The versatility of the sigmatropic sequence is demonstrated within the context of a new formal synthesis of (±)-cerulenin possessing an interesting spectrum of biological activities.
双
烯丙基醚的亲区选择性[2,3]Wittig重排,以及随后的Claisen重排,可以方便地得到(E,E)-4,7-烯
丙二烯醛和烯
丙二烯酸。在具有多种
生物活性的(±)-青霉烯素的新形式合成中,展示了西格马拓扑序列的多功能性。