Preparation of methylenedifluorocyclopropanes 2 through the β-elimination reaction promoted by difluorocyclopropyl anion formed by cleavage of C Si bond with TBAF is described. Base-catalyzed isomerization of 2 to difluorocyclopropene 11 shows the latter structure themodynamically more stable in contrast to non-fluorinated cases. Application of this method to the synthesis of methylenedifluorocyclo-propylglycine (F2MCPG) derivative ...