One-Pot Synthesis of Diethyl 2-Aryl-3-(trifluoroacetyl)-cyclopropane-1,1-dicarboxylates

The reaction of 4-aryl-3-bromo-1,1,1-trifluorobut-3-en-2-ones with diethyl malonate afforded diethyl 2-aryl-3-(trifluoroacetyl)cyclopropane-1,1-dicarboxylates representing a family of donor–acceptor cyclopropanes that are very important precursors for cycloaddition reactions. The reactions with fluorinated α-bromo enones occurred under mild conditions and were complete in a shorter time than similar reactions with fluorine-free analogs. The synthesized cyclopropanes had exclusively trans configuration.