Electrooxidative Dearomatization to Spiroisoxazolines: Application to Total Synthesis of Xanthoisoxazoline B

The synthesis of spiroisoxazoline molecules has been developed via anodic oxidative dearomatization of 4-methoxybenzyl oximes. The reaction is thought to proceed through 5-exo C-O bond-forming cyclization of oxime radicals with arenes on the basis of cyclic voltammetry studies. Moreover, spiroisoxazolines can be built directly from readily available carbonyl tethered phenolics via an oximation/dearomatization cascade. Using this spiroisoxazolization as the key step, the first total synthesis of xanthoisoxazoline B has been achieved in three steps.

Automated summary

The synthesis of spiroisoxazoline molecules via anodic oxidative dearomatization of 4-methoxybenzyl oximes has been developed, leading to the first total synthesis of xanthoisoxazoline B in three steps.