Stereocontrolled synthesis of highly functionalised spirocyclic pyrans†
Abstract
Highly functionalised spirocyclic pyrans can be obtained through the Achmatowicz rearrangement of furyl carbinols by taking advantage of the different rates of reaction for epoxidation and nucleophilic addition. Through this methodology, spirocyclic units of various ring sizes can be selectively generated with complete stereocontrol.