Selectivity in the Reduction of Bicyclic and Polycyclic Derivatives

As with monocyclic ketones, bicyclic ketones show excellent diastereoselectivity upon reduction with hydride reagents. A typical example is the selectivity observed in the reduction of bicyclo[2.2.1]heptan-2-one (315, norbornanone) and 7,7-dimethylbicyclo[2.2.1]heptan-2-one (317). The exo face (path a in 315a) is 

When edge-fused bicyclic (bicyclo[m.n.O]) systems are examined, as shown in Table 4.13,290 they behave very similarly to monocyclic ketones. Reduction of decalone (319) and indanone (320), for example. 

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