The synthesis of β-keto lactones via cyclization of β-keto ester dianions or the cyclization of Meldrum's acid derivatives

~80%

~57%

~88%

~70%

~%

~%

~67%

~%

~%

~%

~47%

~%

~%

~%

~94%

~%

~98%

~%

~%

~%

~%

~%

~%

~%

~%

~35%

~35%

~70%

~76%