The reaction of 1-chloro-1-(trich10rovinyl) eyclopropanes l with potassium hydroxidc/methanol or sodium rnethoxide/methanol yields trimethyl 2-chloro-2- eyclopropylidenorthoacetates 7. which can be quan-titatively converted to the corresponding esters 8 by acid treatment. The methyl 2-chloro-2-cyclopropylidenacetates 8 are highly reactive Mi-chael acceptors, which readily undergo 1.4-addition with soft nucleophilcs ...