Application of Conformation Design in Acyclic Stereoselection: Total Synthesis of Borrelidin as the Crystalline Benzene Solvate
作者:Stephen Hanessian、Yang、Simon Giroux、Vincent Mascitti、Jianguo Ma、Franck Raeppel
DOI:10.1021/ja030139k
日期:2003.11.1
The total synthesis of (-)-borrelidin (treponemycin), a structurally distinct 18-membered macrolide antibiotic, has been achieved. It was isolated as the crystalline benzene solvate, and its structure was confirmed by a single-crystal X-ray analysis. The deoxypropionate subunit consisting of four alternating C-methyl groups with a C(4)-C(10) syn/syn/anti orientation was elaborated by a new method of
(-)-疏螺旋体素(密螺旋体霉素)的全合成,一种结构独特的 18 元大环内酯抗生素,已经实现。它被分离为结晶苯溶剂化物,其结构由单晶 X 射线分析证实。脱氧丙酸亚基由四个交替的 C-甲基基团组成,具有 C(4)-C(10) 顺/顺/反取向,是通过一种新方法对无环 α、β-不饱和酯进行迭代加成,依赖于两个连续的1,3-诱导并以 d-甘油醛作为手性祖体开始。独特的 Z/E 氰基二烯单元是通过应用 Still-Gennari 烯化协议作为单一异构体获得的。γ-羟基环戊烷羧酸亚单元由 L-苹果酸利用 C-乙烯基和 C-烯丙基的顺序引入制备,通过 Grubbs 闭环复分解反应利用无环 α,β-不饱和酯中的 1,2-诱导和碳环化。铜酸盐添加物中 1,3-syn-disposed 脱氧丙酸酯三联体的普遍性基于最小化过渡态中的同戊烷相互作用而合理化。虚拟金刚石晶格被用作描绘无环基材的低能量构象的可视化工具,并通过