12-(酰氧亚氨基)-1,15-十五内酯的合成及结构表征

Synthesis and Characterization of 12-Acyloxyimino-1,15-pentadecanolides

以α-硝基环十二酮为原料, 与丙烯醛加成、扩环并经Nef反应合成了12-氧代-1,15-十五内酯, 再经成肟和酰化及硅胶柱层析分离分别得到12-(酰氧亚氨基)-1,15-十五内酯的顺式及反式异构体.结构经IR, 1H NMR及元素分析确证.通过对个别化合物的单晶X射线分析, 结合1H NMR数据, 分别确定了它们的Z, E构型.结果表明, 12-氧代-1,15-十五内酯成肟时对顺、反异构体的形成缺少明显的选择性, 而目标化合物环骨架的优势构象为[23434], 羰基和肟基位于两个不同的角碳位置.

By the addition with acraldehyde, ring-enlargement and Nef reaction, 12-acyloximino-1, 15-pentadecanolides were synthesized from α-nitro-cyclododecanone. cis- and trans-isomers of 12-acyloxyimi-no-l,15-pentadecanolides were obtained by oximation, O-acylation and silica gel column chromatography separation, respectively. The structure of all the title compounds were confirmed by IR, 1H NMR and elementary analysis. Their configurations and conformations were determined by the crystal X-ray analysis of a representative compound and 1H NMR. The results show that the oximation of 12-oxo-l,15-pentade-canolide displays low selectivity for cis- and trans- isomers and the preferred conformation of the ring skeleton is[23434], with the carbonyl group and oximido group present in the two different corner-carbon positions, respectively.