Intramolecular [2+2] photocycloadditions as an approach towards the right-hand side of solanoeclepin A
作者:Richard H. Blaauw、Jorg C. J. Benningshof、Angeline E. van Ginkel、Jan H. van Maarseveen、Henk Hiemstra
DOI:10.1039/b104165g
日期:——
iododioxenone 6, which allowed facile allylation at C-5 of the dioxenone. Photochemistry with dioxenones 12 and 17 led to novel bicyclo[2.2.0]hexanes 24 and 26. The use of the more rigid lactone precursor 14 led to bicyclo[2.1.1]hexane 25, and allowed the stereoselective synthesis of the complex tricyclic core of solanoeclepin A. The structure of 25 was unequivocally proven by X-ray crystal structure determination
通过分子内[2 + 2]光环加成6-未取代的二恶烯酮进行分子内[2 + 2]光环加成反应,初步合成了马铃薯囊状线虫最活跃的天然孵化剂solaoeclepin A(1)的双环[2.1.1]己烷亚结构。侧链烯烃。环化前体的合成涉及与碘二恶烯酮6进行的非常有效的碘-镁交换反应,这使二恶烯酮在C-5处容易地烯丙基化。用二恶烯酮12和17进行光化学反应生成了新的双环[2.2.0]己烷24和26。刚性更高的内酯前体14的使用产生了双环[2.1.1]己烷25,并允许solanoeclepin A的复杂三环核心的结构的立体选择性合成25被明确地通过X射线晶体结构测定证实。