Bridging of macrodithionolactones to bicyclic systems. Synthesis and modeling of oxapolycyclic frameworks
Bridging of macrodithionolactones to bicyclic systems. Synthesis and modeling of oxapolycyclic frameworks
复制标题
大二硫内酯与双环系统的桥接。
DOI：
10.1021/ja00164a026
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发表时间：
1990
影响因子：
15
通讯作者：
J. Snyder
中科院分区：
文献类型：
--
作者：
K. Nicolaou;C. Hwang;B. Marron;S. Defrees;E. Couladouros;Y. Abe;P. Carroll;J. Snyder
描述了一个涉及大二硫代内酯与双环体系桥接的新反应。制备了一系列大硫内酯，并将其转化为所需的大硫内酯。后一种底物通过暴露于萘化钠诱导在大环上桥接，在碘化甲酯的加入下形成稳定的双环体系。这样得到的混合硫酮通过去除硫转化为许多饱和或不饱和的双环或多环体系。桥接的立体化学遵循顺式和反式产物的相对能量，而不是大环的构象偏好。这被MM2计算和x射线晶体结构测定所证实
A new reaction involving bridging of macrodithionolactones to bicyclic systems is described. A series of macrodiolides was prepared and converted to the requisite macrodithionolactones. The latter substrates were induced to undergo bridging across the macrocyclic ring by exposure to sodium naphthalenide, leading to stable bicyclic systems upon addition of methyl iodide. The mixed thioketals so obtained were converted to a number of saturated or unsaturated bicyclic or polycyclic systems by removal of the sulfurs. The stereochemistry of bridging follows the relative energy of the cis and trans products rather than the conformational preferences of the macrocycles. This is confirmed by MM2 calculations and X-ray crystal structure determinations