合成路线1

The protection of 5(S)-(hydroxymethyl)tetrahydrofuran-2-one with Tbdps-Cl and imidazole gives the silyl ether (II), which is oxidized by means of LiHMDS and MoOPH in THF to yield 5(R)-(tert-butyldiphenylsilyloxymethyl)-3(R)-hydroxytetrahydrofuran-2-one (III). The fluorination of (III) by means of Et2N-SF3 (DAST) in dichloromethane affords 5(R)-(tert-butyldiphenylsilyloxymethyl)-3(S)-fluorotetrahydrofuran-2-one (IV), which is reduced with DIBAL to provide the alcohol (V). The acylation of (V) with Ac2O and pyridine gives the acetate (VI), which is converted into the bromide (VII) by reaction with Tms-Br and BiBr3. The condensation of (VII) with 6-chloro-9-(trimethylsilyl)purine (VIII) yields the glycosylated chloropurine (IX), which is then desilylated by means of TBAF in THF to afford the chloronucleoside (X). Finally, this compound is treated with ammonia in methanol at 100 C in a pressure vessel to provide the target Lodenosine.