Triphenylphosphine-mediated synthesis of 5-oxo-2,5-dihydrofurans through the reaction of dialkyl acetylenedicarboxylates and butane-2,3-dione

Dimethyl or diethyl acetylenedicarboxylates undergo smooth reactions with butane-2,3-dione in the presence of triphenylphosphine to yield highly functionalised 5-oxo-2,5-dihydrofurans; using di-t-b...