The reactions of C(α), O-dilithiooximes, C(α), N-dilithiophenylhydrazones, and C(α), N,N-trilithiohydrazones with diethyl oxalate to give biisoxazoles, bipyrazoles, and pyridazones

Several C(α), O-dilithiooximes were condensed with diethyl oxalate and acid-cyclized to give biisoxazoles. Only dilithio p-fluoroacetophenone phenylhydrazone gave the bipyrazole when condensed with this diester. Other C(α), N-dilithiophenylhydrazones and several C(α), N,N-trilithio-hydrazones were condensed with diethyl oxalate and acid-cyclized to give the intramolecular 4-hydroxy-3-pyridazones. Several non-cyclized intermediates were isolated and a reaction mechanism is presented.