The scope of acid-promoted Fries rearrangements of benzannulated lactones has
been examined. The reaction is applicable to seven-membered lactones
possessing a sufficiently activated aromatic ring but not to six-membered
lactones, and it proceeds in higher yield for diterpenoid lactones than for
lower molecular weight lactones. The structures of the 2,6-methano-bridged
benzoxocin side products (23), (24), and (25) from rearrangement of the
diterpenoid lactone (11) have been assigned.
研究了苯并内酯在酸促进下进行弗里斯重排的范围。
进行了研究。该反应适用于具有足够活化芳香环的七元内酯
但不适用于六元内酯。
二萜内酯的产率高于分子量较低的内酯。
二萜内酯的产率高于分子量较低的内酯。2,6-甲桥苯并氧杂环己烷副产品(23,6-甲桥苯并氧杂环己烷)的结构为
2,6-甲桥苯并氧羰基副产物(23)、(24)和(25)的结构。
二萜内酯 (11) 重排生成的 2,6-甲桥苯并恶嗪副产品 (23)、(24) 和 (25) 的结构已经确定。