hz 1h 7 15 t j 7 8 hz 1h 6 77 s 1h 6 09 d j 4 7 hz 1h 5 90 d j 4 9 hz 1h 3 84 s 3h 3 80 s 3h triethylsilane 6 83 g was added to trifluoroacetic acid 33 13 g that had been pre cooled in an ice bath compound 3 10 g was added to the mixture keeping the temperature below 15 u00b0 c after stirring for 2 h mtbe was added to precipitate the product the slurry was filtered and the product washed with additional mtbe after drying 9 12 g of compound 4 was isolated 1 h nmr dmso d 6 400 mhz u03b4 12 11 br s 1h 7 47 s 1h 7 42 7 38 m 1h 7 14 7 08 m 2h 6 67 s 1h 3 87 3 84 m 8h triethylsilane 7 50 g was added to trifluoroacetic acid 49 02 g that had been pre cooled in an ice bath compound 3 14 65 g was added to the mixture keeping the temperature below 15 u00b0 c after stirring for 1 h a solution of 17 63 g sodium acetate in 147 ml methanol was added the mixture was heated to reflux for 3 hours then cooled to 0 u00b0 c the slurry was filtered and the product washed with additional methanol after drying 12 3 g of compound 4 89 7 yield was isolated 1 h nmr dmso d 6 400 mhz u03b4 12 11 br.