Isoimerubrine is an attractive synthetic target because of its fascinating fused structure of the seven-membered tropone ring and isoquinoline moiety as well as its interesting biological activities. Based on our previous total synthesis of pareitropo...
Isoimerubrine is an attractive synthetic target because of its fascinating fused structure of the seven-membered tropone ring and isoquinoline moiety as well as its interesting biological activities. Based on our previous total synthesis of pareitropone, the key synthetic step for isoimerubrine is the radical anionic coupling of phenolic nitronate for the construction of the annulated tropone ring. We have synthesized the trimethoxy-substituted tropoloisoquinoline rings of isoimerubrine containing the chlorine functional group. They could be useful for the preparation of various analogs of isoimerubrine because the chlorine group could be readily converted into other functional groups. Using this strategy, we have successfully synthesized isoimerubrine and its regioisomer by simple methoxylation.