Enantioselective Synthesis of (-)-10-Hydroxyacutuminine

An enantioselective synthesis of (-)-10-hydroxyacutuminine is reported. Central to our strategy is a photochemical [2+2] cycloaddition that forges two of the quaternary stereocenters present in the acutumine alkaloids. A subsequent retro-aldol/Dieckmann sequence furnishes the spirocyclic cyclopentenone. Efforts to chlorinate the acutumine scaffold at C10 under heterolytic or radical deoxychlorination conditions led to the synthesis of an unexpected cyclopropane-containing pentacycle.

Automated summary

An enantioselective synthesis of (-)-10-hydroxyacutuminine is reported, utilizing a photochemical [2+2] cycloaddition followed by a retro-aldol/Dieckmann sequence. However, attempts to chlorinate the acutumine scaffold at C10 led to the unexpected formation of a cyclopropane-containing pentacycle.