further dried under high vacuum which gave the trifluoroacetic acid salt of compound 3 4 as an oil 116 mg 112 the material was used without purification in the following step r f 0 26 ch 2 cl 2 nh 3 in meoh 7m 9 1 1 h nmr cd 3 od u03b4 8 46 s 1h 8 01 s 1h 7 32 7 25 m 5h 5 84 s 2h 4 66 s 2h 4 44 d j 14 1 hz 1h 4 39 d j 14 1 hz 1h 3 87 dd j 4 4 8 7 hz 1h 3 70 3 58 m 2h 3 44 3 34 m 2h 2 68 dd j 5 3 13 5 hz 1h 2 48 dd j 9 1 13 5 hz 1h 2 42 2 26 m 1h 2 08 s 3h 13 c nmr cd 3 od referenced to the middle methanol peak at 49 0 ppm u03b4 153 2 146 3 141 1 138 8 137 2 129 6 129 5 129 3 114 6 104 1 79 4 73 0 72 5 63 4 49 4 41 6 40 1 33 6 15 5 hrms m h calcd for c 21 h 30 n 5 o 3 s 432 2069 found 432 2059 the product of example 3 5 70 mg 0 11 mmol was dissolved in methanolic ammonia 7m 5 ml and pd black 95 mg 0 89 mmol was added followed by hydrazine hydrate 500 u03bcl 10 3 mmol.