Reduction of 5-Substituted Adamantanones with

The internal C -Cc=o-C -C// dihedral is also affected by the flattening and is 50° in the axial ring compared to 42° in the axial cyclohexanone transition struc- 

The calculated transition structures for both syn and anti attack at 2 (Fig. 6-24) are earlier along the reaction coordinate than the adamantanone transition structure, as measured by the longer Hnu Cc=o distances (syn 1.933, anti 1.934, unsubstituted, 1.899 A) and shorter Al-H u lengths (syn 1.700, anti 1.699, unsubstituted 1.704 A). 

The growing ability of organic chemists to undertake computation reduces the need for simple generalisation of selectivity and offers the potential for calculation of activation barriers as a complementary tool in designing syntheses which require the prediction of facial or diastereoselection. 

The Principle of Conservation of Orbital Symmetry for pericyclic reactions as enunciated by R. B. Woodward and R. Hoffmann comes closest to this description. 

For reaction of an electrophile and a nucleophile it is the interaction of the HOMO of the nucleophile and the LUMO of the electrophile that results in the more important frontier orbital interaction, consistent with donation of electron density of the nucleophile to the electrophile. 

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Calculations on the Reduction of 5-Substituted Adamantanones with AlHj 177... 

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