[CH2:1]=[C:2]1[C@H:9]([CH3:10])[O:8][C@@H:5]([O:6]C)[CH2:4][C@@H:3]1[NH:11][C:12](=[O:17])[C:13]([F:16])([F:15])[F:14].C[C@H]1[C@H](C)O[C@@H](OC)C[C@@H]1NC(=O)C(F)(F)F.C(Cl)(Cl)Cl>CO.[Pd].C(O)(=O)C.O>[CH3:1][C@H:2]1[C@H:9]([CH3:10])[O:8][C@@H:5]([OH:6])[CH2:4][C@@H:3]1[NH:11][C:12](=[O:17])[C:13]([F:16])([F:15])[F:14]
Stereoselective reduction of 0.5 g of the intermediate VIII (prepared as described in Example 1) in 40 ml of methanol in the presence of 0.5 g of 20% palladium on charcoal under a pressure of 20 atmospheres gave, in quantitative yield, methyl 2,3,4,6-tetradeoxy-4-C-methyl-3-trifluoroacetamido-L-arabino-hexopyranoside (XI) as a white solid: m.p. 132°-134° C., [α]D23° -82° (c=0.5, CHCl3). The PMR spectrum (CDCl3) showed absorptions at: 0.90 (d, CH3 --C--4), 1.23 (d, CH3 --C--5), 1.26 (m, H--C--4), 3.42 (s, OCH3), 3.70 (dq, H--C--5), 4.20 (m, H--C--3) and 4.87 δ (dd, H--C--1). A solution of 0.385 g, 1.5 mmol of XI in 7 ml of acetic acid and 28 ml of water was heated at 100° C. for two hours and then evaporated to dryness to give, in quantitative yield, 2,3,4,6-tetradeoxy-4-C-methyl-3-trifluoroacetamido-α-L-arabino-hexopyranose (XII) as a white solid: m.p. 158°-159° C., [α]D23° -62° (c=0.5, CHCl3).
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