Meldrum's Acid - Ketene Formation

Ketene Formation

Meldrum's acid displays thermal instability. At high temperatures, Meldrum's acid undergoes a pericyclic reaction that releases acetone and carbon dioxide and produces a highly reactive ketene compound. Ketene intermediates can be isolated using flash vacuum pyrolysis (FVP) of Meldrum's acid at high temperatures. These highly electrophilic ketenes allow various chemical reactions to take place by reacting the unstable ketene with other chemicals. Alternately, the pyrolysis can be performed in solution, allowing a one-pot reaction with chemicals already present rather than isolating the unstable ketene intermediate. With relative simplicity, is possible to form new C–C bonds, rings, amides, esters, and acids. The ability to form such diverse products makes Meldrum's acid a very useful reagent for synthetic chemists.