The reported structure of the natural calafianin (1) and its isomer in the epoxide region 13 were successfully synthesized through the cis- and trans-spiroisoxazoline compounds, which were produced by electrochemical oxidation of the hydroxyimino-phenol derivative 7, followed by Zn[BH4]2 reduction. Comparison of the spectroscopic data of the synthetic (±)-1 and (±)-13 resulted in structural revision of the natural calafianin to 13, possessing the trans-relationship between an epoxide and an oxygen of the isoxazoline. In addition, a significant difference of antimicrobial activity between 1 and 13 is discussed.
报道的自然卡拉法宁(1)及其异构体在环氧区域13通过顺式和反式螺
异噁唑啉化合物成功合成,这些化合物是通过对羟亚
氨基苯酚衍
生物7的电
化学氧化产物,再经过Zn[BH4]2还原得到的。合成的(±)-1和(±)-13的光谱数据比较导致了对自然卡拉法宁结构的修订,确认其为13,具有环氧和
异噁唑啉氧之间的反式关系。此外,还讨论了1和13之间抗菌活性显著差异。