Design and Synthesis of 5'-Iodoneplanocin A and Its Analogues as Potential S-Adenosylhomocysteine Hydrolase Inhibitor

5"-Iodoneplanocin A (1) and its analogues 2 and 3 were designed and synthesized as potential SAHH inhibitor via iodocyclopentenol 6, which was prepared using a Michael addition-iodination-elimination process. All final compounds did not show antiviral activity, maybe due to a steric hindrance induced by 5"-iodo substituent.