US 2020/0133122 Al  99  Apr. 30, 2020  -continued  0  CF3  A,......s03- 0  C  F2  >y 0 ~ 0 J:,:s~  0  CF3  o~0Ac,......s03- F2  0  NYO  0  0  AcO  0  [0167]  In formula (3B), W1’ 1  and W1’ 2  are each indepen› dently fluorine or a C$_{1 }$-C$_{40 }$monovalent hydrocarbon group  which may contain a heteroatom. The monovalent hydro› carbon groups may be straight, branched or cyclic, and  examples thereof are as exemplified above for R 112 . Pref› erably  W1’ 1  and W1’ 2  each are fluorine or a straight C$_{1 }$-C$_{4 }$ fluorinated alkyl group. A pair of W1’ 1  and W1’ 2  may bond  together to form a ring with the linkage (-CF$_{2}$-SO$_{2}$ - N--SO$_{2}$----CF $_{2}$-) to which they are attached, and prefer› ably the pair is a fluorinated ethylene or fluorinated propyl› ene group.  [0168]  In formula (3C),  Rf’cl, wc 2  and  Wc3  are each inde› pendently fluorine or a C$_{1 }$-C$_{40 }$ monovalent hydrocarbon  group which may contain a heteroatom. The monovalent  hydrocarbon groups may be straight, branched or cyclic, and  examples thereof are as exemplified above for R  112 . Pref› erably wc1,  wc 2  and  Wc3  each are fluorine or a straight  cl  -C4 fluorinated alkyl group. A pair of wc1 and  wc 2  may  bond together to form a ring with the linkage (--CF  2 - SO2-c--SO 2 -CF  2 -) to which they are attached, and  preferably the pair is a fluorinated ethylene or fluorinated  propylene group.  [0169]  In formula (3D),  wd  is a Cl-C40 monovalent hydro› carbon group which may contain a heteroatom. The mon› ovalent hydrocarbon groups may be straight, branched or  cyclic, and examples thereof are as exemplified above for  R112_  [0170]  With respect to the synthesis of the sulfonium salt  having an anion of formula (3D), reference is made to JP-A  2010-215608 and JP-A 2014-133723.  [0171]  Examples of the anion having formula (3D) are  shown below, but not limited thereto.  ,  l $_{0}$~so, ~ $_{0}$~so;  A  ,  c~  u  c~  ~ $_{0}$~so;  u  CF3  ~o~s~  llJ  CF3  o o~s~  CF3  0  W $_{0}$~s~  CF3 