Carbocyclic 4'-Epiformycin.

Formycin is a naturally occurring biologically responsive C-nucleoside. In pursuing the design and syntheses of novel C-nucleosides, convenient access to carbocyclic C-nucleosides based on the formycin framework was a goal. One such target was carbocyclic 4'-epiformycin (4). This compound is reported via a procedure based on an asymmetric aldol/ring closure methathesis strategy. To provide a preliminary glimpse into the biological characterization of 4 an antiviral assay was conducted. Target 4 was found to be inactive and to lack cytotoxicity to the host cells.