The I–K fragment (C31–C49) of the ciguatoxin CTX3C has been synthesized from a simple chiral pool derived tetrahydropyranyl alcohol. An efficient gold-catalyzed cyclization reaction of a γ′-hydroxy ynone has been used to accomplish efficient closure of ring K under mild conditions. The resulting vinylogous ester has been elaborated to give a complete tricyclic fragment bearing the dimethyl-substituted
                                    雪卡毒素 CTX3C 的 I-K 片段 (C31-C49) 是由衍生自
四氢吡喃醇的简单手性池合成的。 γ′-羟基炔酮的高效
金催化环化反应已被用来在温和条件下实现 K 环的有效闭合。所得到的插烯酯经过精心设计,可得到完整的
三环片段,该片段带有组装靶标的 LM 螺环
缩醛部分所需的二甲基取代的侧链。