79 5 3f colorless amorphous 75 yield 91 3 purity 1 h nmr 300 mhz cdcl 3 u03b4 1 88 s 3h 2 79 t 2h j 19 1 hz 4 98 s 1h 5 11 s 1h 19 f nmr 272 mhz cdcl 3 u03b4 124 8 2f u2212 122 0 2f u2212 121 5 2f u2212 120 5 14f u2212 111 5 2f u2212 79 5 3f colorless amorphous 84 yield 92 0 purity 1 h nmr 300 mhz cdcl 3 u03b4 1 88 s 3h 2 79 t 2h j 19 3 hz 4 97 s 1h 5 11 s 1h 19 f nmr 272 mhz cdcl 3 u03b4 185 0 1f u2212 122 4 2f u2212 120 5 4f u2212 119 6 2f u2212 113 9 2f u2212 111 8 2f u2212 70 8 6f colorless amorphous 93 yield 97 5 purity 1 h nmr 300 mhz cdcl 3 u03b4 3 29 t 2h j 18 6 hz 5 39 s 1h 5 65 s 1h 7 29 7 42 m 5h 19 f nmr 272 mhz cdcl 3 u03b4 124 9 2f u2212 122 1 2f u2212 121 5 2f u2212 120 7 4f u2212 120 4 2f u2212 111 2 2f u2212 79 5 3f.