Thermolysis of γ-Fluorosulfonyl perfluorobutanoic acid derivatives: New synthetic routes for perfluorinated cyclic sulfones

Recent Advances in the Synthesis and Transformation of Carbamoyl Fluorides, Fluoroformates, and Their Analogues

“…In 2020, Tverdomed and Hirschberg described a useful method for the conversion of n ‐C 3 F 7 OCF(CF 3 )CF 2 OCF=CF 2 (PPVE‐2, 240 ) to n ‐C 3 F 7 OCF=CF 2 (PPVE‐1, 245 ) via a fluoroformate intermediate (Scheme 43). [74] The procedure involved V 2 O 5 ‐catalyzed oxidation of 240 with O 2 to furnish a mixture of carbonyl fluorides ( 241 and 242 ), which were subjected to hydrolysis with KOH to give a mixture of potassium salts ( 243 and 244 , M = K) in quantitative yield. Subsequently, thermolysis of these salts gave rise to an inseparable mixture of 245 and perfluoro‐2‐propoxypropanoyl fluoride that were saponified with excess Na 2 CO 3 to afford sodium perfluoro‐2‐propoxypropionate ( 243 , M = Na) and 245 .…”

“…The remaining mixture of sodium salts was further decarboxylated in high‐vacuum at 220–240 °C to produce the second portion of 245 in 70 % yield. Referring to the starting 240 , the total yield of 245 was 55 % [74] …”