Talk:Module1pl506

1.1 Energies and structures for 1 and 2 are fine. Why is 2 kinetically preferred? What structural features explain the higher torsional strain in 2? Your explanation for the higher bending strain in 3 is confusing.

1.2 What are the energies for 5 and 7? Structures look OK. There should be another (less stable) conformer for 7 with the carbonyl "up". How do you explain the stereocontrol in the addition to 7?

1.3 Your structure 10 has the cyclohexane in a boat conformation - but the strange thing is that the energy is correct for the chair conformer! I don't believe the energy quoted is for the structure given. Did you find the chair but accidentally include the boat structure?

1.4 Your 4 structures are OK. However, they won't be the same as the ones in the paper, because the authors said that they would consider only conformations with the OH group equatorial. Some of yours have it axial. This will explain why your results differ from those in the paper. Explaining why 13 cyclises faster than 14 is quite subtle, and we now think requires more sophisticated analysis/modelling than the paper suggests.

1.5 Your orbitals look odd - the HOMO should have a large coefficient on the alkene. You should also have discussed the reasons for the differences between the C=C and C-Cl stretches in the various structures

Mini-project: You chose R=iPr (i.e. CH(CH3)2), but your structures have R=nPr... These alkyl groups would give quite distinct NMRs. The fact that your structures have negative frequencies is very worrying - you've probably optimised saddle-point structures. You should have been able to find real minima, with no imaginary frequencies. You didn't discuss what you think would be the best spectroscopic method to tell these isomers apart. Nor did you discuss (in terms of mechanism) why this example gives a mixture of isomers.

Overall - you got most of the calculations done, but didn't really relate the results to chemical thinking about structure and reactivity.