disclosed are processes for the production of fluorinated olefins , preferably adapted to commercialization of cf 3 cf ═ ch 2 . three steps may be used in preferred embodiments in which a feedstock such as ccl 2 ═ cclch 2 cl is fluorinated to synthesize a compound such as cf 3 ccl ═ ch 2 . the cf 3 ccl ═ ch 2 is preferably converted to cf 3 cfclch 3 using a sbcl 5 as the catalyst which is then transformed selectively to 1234yf . for the first step , a mixture of cr 2 o 3 and fecl 3 / c is preferably used as the catalyst to achieve high selectivity to cf 3 ccl ═ ch 2 . in the second step , sbcl 5 / c is preferably used as the selective catalyst for transforming 1233xf to 244 - isomer , cf 3 cfclch 3 . the intermediates are preferably isolated and purified by distillation and used in the next step without further purification , preferably to a purity level of greater than about 95 %.