A CONVENIENT SYNTHESIS OF ACYCLIC ADENOSINES WITH AN UNSATURATED SIDE-CHAIN BY MODIFICATION OF 9-(2,3-O-ISOPROPYLIDENE-D-RIBITYL)ADENINE

In expectation of discovering their antiviral activity, acyclic adenos ine derivatives 7, 11, 12, and 16 were designed as analogs of neplanoc in A (NPA) and L-eritadenine which are strong inhibitors of S-adenosyl -L-homocysteine hydrolase. The 1',5'-seco-analog of 4'-deoxymethyl-NPA (DHCA) 7 was synthesized by dideoxygenation of 9-(2, 3-O-isopropylide ne-D-ribityl)adenine (2). Acyclic DHCA analogs 11 and 16 were obtained by Wittig reaction of the aldehyde 3 with Ph3P=CHCO2Et and Ph3P=CHCN, respectively. Hydrolysis of the ester 11 afforded a vinylog of L-erit adenine 12. The synthesized acyclic nucleosides 7, 10, and 11 were eva luated for antiviral activity, however, none of them showed any signif icant antiviral activity.