## 1 Introduction  
Nowadays, organofluorine compounds are essential materials, especially in recent IT, electronics, and medical applications [1]. For example, the low surface energy of an organofluorine compound leads to water repellent and oil repellent properties, so that it is utilized as surface treating agents for water-and-oil repellent film. Therefore, it is expected that an anti-staining coating material for glass, for example, for automobiles or displays (a liquid crystal display, a CRT display, a projection display, a plasma display, an EL display or the like), could be achieved by an organofluorine compound. One such compound **1** may be a candidate [2,3]. \[\mathrm{CF}_{3}(\mathrm{CF}_{2})_{7}(\mathrm{CH}_{2})_{2}\mathrm{SiX}_{3} \mathrm{[X=OCH}_{3}\mathrm{,\,\,NCO]}\] Compound **1**  
When the compound **1** is applied to the surface of a substrate, the hydrolyzable groups are hydrolyzed by hydroxyl groups of the substrate or moisture on the substrate to form silanol groups. Once the silanol groups are bonded to the substrate, perfluoroxyl groups will be oriented on the atmosphere side, so that the coating film made of the compound **1** exhibits water repellency [4]. However, as perfluoroalkyl groups are highly crystalline and stiff, the coating film made of the compound **1** does not have enough efficiency for the removal of oil-and-fat stains. To solve the problem, a compound having a perfluoropolyether group **2** was reported [5]. \[\mathrm{CF}_{3}\mathrm{CF}_{2}\mathrm{CF}_{2}\mathrm{O}\mathrm{-}(\mathrm{CF }_{2}\mathrm{CF}_{2}\mathrm{C}_{2}\mathrm{O})_{n}\mathrm{-}\mathrm{CF}_{2} \mathrm{CF}_{2}(\mathrm{CH}_{2})_{3}\mathrm{Si}(\mathrm{OCH}_{3})_{3}\] Compound **2**  
The perfluoropolyether (PFPE) group has a flexible structure, because stiff perfluoroalkyl groups are separated by oxygen atoms and C-O-C bonding have high mobility, so that the coating film made of the compound **2** is excellent in its efficiency in removing oil-and-fat stains, and also has water and oil repellency. However, the mobility of the PFPE groups in **2** cannot be regarded as sufficient, and the efficiency for removal of oil-and-fat stains is not enough, because the ratio of oxygen atoms to carbon atoms in the PFPE groups is still small. From the viewpoint of molecular design, \(\mathrm{-}(\mathrm{CF}_{2}\mathrm{CF}_{2}\mathrm{O})\mathrm{-}\) as a repeating unit is ideal. However, there has not been a synthetic method for creating such a molecule, while it is possible to utilize the industrial intermediate of fluorinated oil to synthesize **2**. An organofluorine compound also shows chemical and thermal stability, derived from the nature of a C-F bond. Although highly polarized, the C-F bond gains stability from the resultant electrostatic attraction between C and F atoms [6]. Thus, because of their high thermal and chemical stability and conductivity, perfluorinated sulfonic acid ionomers are often used in polymer electrolyte membranes (PEMs) of fuel cells [7],. Their performance is, however, still not enough. To achieve much higher conductivity, it is necessary to increase the number of sulfonyl groups per unit. On the other hand, PEMs should have a certain mechanical strength to assemble membrane electrode assemblies. In the event that conventional monosulfonated monomers are increasingly used to raise this number, the copolymer obtained will have many branches, and the mechanical strength of the PEM from the copolymer decreases. A bifunctional monomer is expected to overcome this dilemma. However, there has not been a feasible synthetic method to realize such a molecule. On the other hand, we have reported an entirely new synthetic method for perfluorinated molecules, the PERFECT (PERFluorination of an Esterified Compound then Thermolysis) process [8], whichmakes it possible to create new fluorinated compounds because it utilizes organic synthesis in hydrocarbon molecules. For example, a nonfluorinated primary alcohol can be converted to the corresponding perfluorinated acyl fluoride (Scheme 1).