作者:Alois Fürstner、Anne-Sophie Castanet、Karin Radkowski、Christian W. Lehmann
DOI:10.1021/jo026686q
日期:2003.2.1
A concise total synthesis of citreofuran 4 is described, a structurally unique octaketide derivative belonging to the curvularin family. Key steps involve the elaboration of orsellinic acid methyl ester 5 to acid 14, which converts, on attempted formation of the corresponding acid chloride, to the 3-alkoxyisocoumarin derivative 20. This heterocycle can be used as an activated ester to give ketone 21
描述了一种简明的全合成呋喃丁草醚4,它是一种结构上独特的occurtide衍生物,属于curvularin家族。关键步骤涉及将奥山梨酸甲酯5精制为酸14,在尝试形成相应的酰氯时,将其转化为3-烷氧基异香豆素衍生物20。该杂环可用作活化酯,经处理可得到酮21在存在TMSC1的情况下,用3-戊炔基溴化镁作为活化剂。(tBuO)(3)W [三键] CCMe(3)催化的二炔21的闭环炔烃复分解(RCAM)提供了应变的环炔烃22。酸处理使其三键易于受到相邻羰基的亲核攻击,从而导致环戊环芳香化,并形成完整的瓜叶呋喃骨架。X射线晶体学研究揭示了有关该天然产物的构象细节。最后,显示了4及其受保护的前体23能够在氧化条件下切割双链DNA。