The tricyclo[2.1.0.02,5]pentan-3-one system: a new probe for the study of π-facial selectivity in nucleophilic additions

Monosubstituted tricyclo[2.1.0.02,5]pentan-3-one derivatives have been synthesised and subjected to hydride reduction. Quite unexpectedly and in contrast to earlier observations in related systems, anti-selectivity has been encountered in these substrates. Computational studies employing various models reproduce the observed facial preference and indicate that the causative factor for the anti-preference could be the polarization of the C1C5 strained σ bond.