Certain fluorinated cyclobutenes have been found to undergo a “halogen-metal exchange” with Grignard However, reagents in the following manner where A is Br and B is C1 or Br, and also where A is I and B is Br. if A is bromine and B is fluorine, a competing reaction was also observed to take place. The cyclobutenyl Grignard reagent in which B is chlorine was found to undergo rearrangement. Reaction of the cyclic Grignard reagent with water and ...
