SYNTHESIS OF 5'-O-OLIGOPEPTIDE DERIVATIVES OF URIDINE AS INHIBITORS OF UDP-GLUCURONOSYLTRANSFERASE

In order to design potential inhibitors of UDP-glucuronosyltransferase , the synthesis of some 5'-O-oligopeptide derivatives of uridine is pr esented. zyl-L-seryl-L-valyl)-2',3'-O-isopropylideneuridine (1) was sy nthesized by the DCC/HOBt method from N-tert.butyloxycarbonyl-O-benzyl -L-serine and 5'-O-L-valyl-2', 3'-O-isopropylideneuridine in 95% yield . In a similar way, yl-O-benzyl-L-seryl)-2',3'-O-isopropylideneuridine (2) was obtained from N-tert.butyloxycarbonyl-L-valine and O-(O-benzy l-L-seryl)-2',3'-O-isopropylideneuridine in 93% yield. Treatment of 1 and 2 with HCl/EtOAc at room temperature for 30 min led to removal of both Boc and 2',3'-O-isopropylidene groups. 5'-O-(O-Benzyl-L-seryl-L-v alyl)-uridine (3) and 5'-O-(L-valyl-O-benzyl-L-seryl)-uridine (4) were obtained in 94% and 91% yields, respectively.