Substrate-directed divergent annulations of sulfur ylides: synthesis of functionalized bispirocyclopentane and bispirocyclopropane derivatives

Herein, an efficient, substrate-directed divergent [2+3]/[2+1] annulation of tetra-substituted oxa-dienes and allylic sulfur ylides has been successfully developed. Under precise annulation regulation, a series of functionalized bispirocyclopentane and bispirocyclopropane derivatives...