Stereoselective Ring‐Opening of <i>gem</i>‐Difluorocyclopropanes: An Entry to Stereo‐defined (<i>E</i>,<i>E</i>)‐ and (<i>E</i>,<i>Z</i>)‐Conjugated Fluorodienes

Abstract

The ring-opening of gem-difluorocyclopropyl acetaldehydes producing selectively (E,E)- and (E,Z)-conjugated fluorodienals is described. Two stereo-divergent methods are presented to access both stereoisomers from a common precursor, in high yield and selectivity. The mechanistic aspect of these transformations is discussed.