C([O-])(=O)C.[Na+].[F:6][C:7]([F:28])([F:27])[C:8]([NH:10][C@@H:11]1[C@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@H:15]([CH3:21])[O:14][C@H:13](Br)[C@@H:12]1OC(=O)C)=[O:9]>[Zn].C(O)(=O)C>[F:28][C:7]([F:6])([F:27])[C:8]([NH:10][C@@H:11]1[C@H:16]([O:17][C:18](=[O:20])[CH3:19])[C@H:15]([CH3:21])[O:14][CH:13]=[CH:12]1)=[O:9]To a mixture of 18 g. of zinc dust and 1.8 g. of cupric sulfate in 60 ml. of 50% aqueous acetic acid containing 25 g. of sodium acetate, 10 g. of the product of Examples 10 and 11 in 10 ml. of acetic acid is added dropwise at -10° C. The reaction is continued for 4 hours at -10° C., after which the zinc dust and copper are removed by filtration, 50 g. of ice is added to the filtrate, and the filtrate is extracted three times with chloroform. The combined extracts are washed with water, a cold saturated sodium hydrogen carbonate solution, and water. After the chloroform solution is dried over anhydrous magnesium sulfate, it is evaporated in vacuo to a heavy syrup. The syrupy residue is crystallized from a mixture of ether-petroleum ether to give 4.7 g. (77% yield) of 3-trifluoroacetamido-4-O-acetyl-1,2,3,6-tetradeoxy-L-lyxo-hex-1-enepyranose.
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