Both enantiomers of 6′-Isoneplanocin

: Both enantiomers of the isomer of neplanocin where the C-4' hydroxymethyl has been displaced to the 6'-position (that is, 6'-isoneplanocin) have been prepared in 5 steps from known, protected iodocyclopentenones. Both products were evaluated against a number of DNA and RNA viruses and found to be inactive. This observation is suggested to be due to the displacement of the C-4' hydroxymethyl of neplanocin (in the D-like form) away from the lysine425 of S-adenosylhomocysteine hydrolase, which is important for inhibition by neplanocin and, in turn, its antiviral activity.