合成路线1

Catalytic hydrogenation of dihydrofuranone (I) over Pd/C afforded the saturated lactone (II). Treatment of (II) with chlorotrimethylsilane and lithium hexamethyldisilazide produced the silyl enol ether (III) which, without isolation, was treated with phenylselenenyl bromide to yield the trans-selenide (IV). Lactone reduction by means of DIBAL followed by acetylation of the resulting lactol (Va-b) gave acetate (VIa-b). The glycosylation of the silylated fluorouracil (VII) with (VIa-b) in the presence of trimethylsilyl triflate furnished adduct (VIIIa-b). Subsequent oxidative elimination of the phenylselenenyl group of (VIIIa-b) via an intermediate selenoxide produced the dihydrofuran derivative (IX), which was finally desilylated by treatment with tetrabutylammonium fluoride.