Corrigendum to “Fluorinated methylenecyclopropane analogues of nucleosides. Synthesis and antiviral activity of (Z)- and (E)-9-{[(2-fluoromethyl-2-hydroxymethyl)-cyclopropylidene]methyl}adenine and -guanine” [Bioorg. Med. Chem. 16 (2008) 2148–2155]