presented. The pivotal intermediate is identified as macrocycle III. The two interior bonds (C4a–C12a and C5a–C11a) are to be constructed through sequential transannular Michael additions (III–II) and compression-promoted transannular isoxazole alkylations from intermediate II.
提出了一种新的
四环素核心结构方法。关键中间体被确定为大环III。两个内部键(C4a–C12a和C5a–C11a)将通过顺序的跨环Michael加成(III – II)和由中间体II压缩促进的跨环
异恶唑烷基化来构建。