Stereoselective Synthesis of Both Stereoisomers of β-Fluorostyrene Derivatives from a Common Intermediate

The stereoselective synthesis of both cis- and trans-beta-fluorostyrene derivatives from a common intermediate, (Z)-1-aryl-2-fluoro-1-(trimethylsilyl)ethenes, Is described. The trans isomers are obtained by a stereospecific replacement of the silyl group In the presence of water and a fluoride source, whereas the preparation of the cis Isomers Is achieved by a bromination/desilicobromination sequence followed by reduction of the newly created C-Br bond. A stereoselective transformation of both stereoisomers of beta-fluorostyrene is also presented.