User talk:Gg207

Cp dimers: Energies for 1 and 2 OK, although the ChemDraw structure for 2 is wrong (it has a trans-ring junction!). Your explanation for the endo-Diels-Alder would be much clearer with diagrams to show the orbital interactions you're talking about. Sadly you haven't given your energies for structures 3 and 4, nor most of the components contributing to them. You're right to look at the role of bend energy though.

NAD: Your Jmol structure for 5 looks good, but it's a pity you haven't quoted its energy. For 7, it should actually be possible to locate both up and down isomers. You've found the lower energy of the two, the down one, so your analysis of the reaction outcome is OK.

Taxol: You've correctly got the "down" isomer as the lower in energy, although your energies seem a bit odd. I can't get the Jmol buttons to work, so I can't rotate your structures to check them. In fact they CAN interconvert, as the lab script says! Would have been good to have more discussion as to exactly why the alkenes are unreactive (in terms of specific structural features)

Carbene: In fact, you CAN tell something about relative alkene reactivity from your HOMO picture! Your IR frequencies are good, although you've put the exo and endo C=C the wrong way round for 12.

Mini-project: Good to see you found quite a nice example! Your intro gives too much experimental detail of the synthetic route, and in fact you haven't shown/discussed the mechanism for the key allyl silane addition step! Did you consider an alternative conformer for the cis-isomer, where the OSi unit is axial and the allyl equatorial? Any comments on how well the 13C match the experimental values, and whether it could have reliably predicted which isomer was which? I don't think the TBS carbons are a good choice for comparison, but the C1 and C2 values look to agree well. Any ideas why the calculated carbonyl C value is so far off the experimental? You've got the dihedral angles for the cis- and trans-isomers the wrong way round (the trans is larger).