| Abstract
| - Two strategies were tried to synthesize 3‘-deoxy-3‘-difluoromethyl azanucleosides. After the failureof the first route, the key intermediate 12 from trans-4-hydroxyproline 7 in 8 steps wasstereoselectively prepared. The alcohol 12 was subjected to selective protection, oxidation, anddifluoromethylenation to afford the fluorinated compound 18, whose hydrogenation was thensystematically investigated. After a series of transformations of protecting groups, the resultantcompounds 22 and 23 were oxidized to the desired lactams 24 and 25, which were successfullyutilized to synthesize our target molecules, 3‘-deoxy-3‘-difluoromethyl azanucleosides 33, 34a, 34b,and 35.
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