Talk:Mod:ivyzhang

1.1 Energies are very good. Thermodynamic vs. kinetic control is addressed well. The bending energy is indeed the major destabilisation in the dihydro derivatives and it is a measure of departure from ideal bond angle; in this case the bond angles that are not ideal are those of the double bonds and the deviation from ideal angle is worse for the double bond in the bicyclic system.

1.2 Energies obtained are good and the reason for stereocontrol is well explained. It is not possible to directly compare the energies of the products and starting materials however.

1.3 The CO-down isomer is indeed the most stable and your energy values are about right. This alkene is specifically “hyperstable” because the product of hydrogenation would be less stable (due to steric crowding around the polycyclic system).

1.4 Energies are about right; the reason for the difference in reaction rate is not known. It is possible to orientate each isomer into a reacting conformation (in contrast to what the paper implies). The correct best conformation for reaction has the Burgi-Dunitz trajectory and places the reacting groups close in space. This is also the reason in general why these intramolecular reactions are fast: the hydroxyl group is close to react and doesn’t have to arrive via diffusion to collide.

1.5 The MO diagrams and structures look correct. The IR stretches are good and the differences between the diene and dihydro compound are discussed well with correct reasoning.

MP A good amount of data has been calculated and the molecule is an interesting one. It may have been beneficial to see the differences between experimental and calculated NMR data tabulated. Also consider how the authors of the paper in question differentiate between the two compounds.