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Talk:Mod:JPS1123

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TOTAL MARK: 95%

General comments: Well done including an introduction of what is going to be studied in this exercise, as well as a brief description of the different programmes/theory used. Perhaps you could also have added a brief discussion about the methods used for the calculations, (i.e. MM vs DFT). Overall the lay out of the report is very neat and clear.

1.1 Part 1 (45%) 1.1.1 Formation and Hydrogenation of Cyclopentadiene Dimer (10%)- 8/10 I. Well done obtaining the correct structures for the exo and end and discussing the kinetic control of the equilibrium. But, you should have included a quote to the literature here to support statements like 'However it is known that the endo product is the major product of the reaction and thus the reaction must be under kinetic control.' Also, a more detailed comparison of the different energy terms is required to be awarded with the full mark for this exercise. - 3/5

II. This part is much better done, you include what I told you that it was missing in your previous response, well done! - 5/5

1.1.2 Atropisomerism in an Intermediate related to the Synthesis of Taxol (10%)- 8.5/10 Well done obtaining the correct conformations, specially obtaining such a low energy for molecule 9! You obtain the correct ranking, also I think that you made a mistake in your table though, where is written optimized boat it should be chair instead of boat, however I think that you know that that conformation is a chair as you mention it in the text. Be careful with this small mistakes, anyway I am not going to reduce your mark for this. - 5/5

Good discussion about the hyperstability of the these alkenes, also you could have modelled the parent hydrocarbons with the single bond in order to support your statement, it would have been a very good contribution to your discussion that would have given you the full mark for this question. Next time, try and use more the help of the demonstrators, as this would have been told to you… 3.5/5

1.1.3 Taxol NMR - Spectroscopic Simulation using Quantum Mechanics (25%) - 23/25 Good job calculating the spectrum and finding literature value for the, However, you could have compared them by doing some data manipulations, i.e. you could have averaged the chemical shift of the protons with the same chemical environment. Good and complete discussion even though missing the comparison of the HNMR.

1.2 Part 2 (55%)

1.2.1 The Crystal Structures of the Shi Catalyst and the Jacobsen Catalyst (5%)- 5/5 Well done finding the crystal structures and describing their major features.

1.2.2 The Calculated NMR Properties of the Epoxides (5%)- 2.5/5 You are missing the most important part of this exercise, the comparison with the literature values. Sorry, but even though you did the calculations you cannot be awarded with the dull mark for this exercise.

1.2.3 The Assignment of the Absolute Configurations for Alkenes 2 and 4 (35%)- 35+3 Well done calculating and finding the OR values in the literature and very interesting discussion, next time, present data like this in a table too, this would help the reader following your text much better. Also, good job with the VCD, next time, try and put them in the same scale or at least the same size. - 15/15%

Regarding the enantiomeric excess, great job! You only needed to do one shi and one jacobsen, but you have done extra job. The results are very nicely presented and discussed as well as compared with literature, great effort! I am going to give you a bonus for this exercise.


1.2.4 NCI and QTAIM Analysis for the Transition State- 6/6 Well done and nice discussion.

1.2.6 New Candidates- 4/4 Well done!