43  US 7,511,179 B2  44  (MEC-31 is a fluorinating agent available from DAIKIN  INDUSTRIES, LTD.)  Also a monomer represented by:  which can introduce a structural unit represented by:  and further can be obtained by ( co )polymerization of a novel  monomer represented by:  and example of a preparation process thereof is the following  preparation scheme (5).  Preparation Scheme (5)  is a novel compound, and example of a preparation process  thereof is the following preparation scheme ( 4).  (MEC-11 is a fluorinating agent available from DAIKIN  INDUSTRIES, LTD.)  Also a structural unit represented by:  can be obtained by cyclic polymerization of a diene com› pound represented by:  It is preferable that the fluorine-containing polymer having  OH group for the photoresist composition of the present  Pd  cat  0  0  F3C~CF3  ~OC02Me  V  TMSCF3  KF  F3COC  COCOF3  ~  F3C  CF3  F3C  CF3  OH OH  V  EtO 2 C  CO2Et  TMSCF3  KF  ~  PhCH=RuC12(PChx3)2  F3C  CF3  F3C  CF3  OH OH  or  Preparation scheme (4)  0  0  ~  MEC-11  F3C  CF3  0  0  ,,eye,, ,,cm-cHMelli  F3C  CF3  2) PG-Cl  F 3 ~  (cF 3  PhCH=RuC12(PCHx3)2  PG-0~0-PG  F3C  CF3  F3C~CF3 _____!!:__  PG-o.,,.,  A  "o-PG  F3CVCF3  HO  OH  F3C  CF3  F3C  CF3 