Fluorinated P-lactones

Synthetic approaches to fluorinated p-lactones (oxetane-2-ones) are very similar to oxetane synthesis. Usually p-lactones are prepared either by cycloaddition of ketenes to aldehydes or ketones or by cyclodehydration of p-hydroxycarboxylic acids. 

Pyrolysis of 59 typically results in fluorinated p-lactones extrusion of CO2 and high-yield formation of (Cp3)2C=CH2. The reaction is used for the synthesis of this olefin on commercial scale. 

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