Orgo Lab Report

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Yonah Ziemba

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Oct 10, 2011, 2:48:25 PM10/10/11

to NYU Orgo Postbacc Group

This weeks lab report is being graded by Abel Navarro, and he wrote on Blackboard that he wants 3 questions answered in the report. I can imagine what he wants for two of them, but I'm not sure what he's getting at with the third. If you have an idea, please let us know.
(And if you think I'm mistaken in the first two answers, then certainly please let us all know.)

Question: Why is cis or trans product preferred? Why is only one product observed and not a 1:1 mixture?
Answer: Trans is more stable because the OH groups are situated further apart from each other, and therefore have weaker repulsions.

Question: According to the results, is trans-diol more polar than the cis-diol?
Answer: No, cis is more polar. The silica plate is polar and the polar cis travels slower because it is more attracted to the stationary polar silica.

Question: Explain the purpose of the staining with anisaldehyde. Why do the spot become colored with this reagent?
Answer: ??? (It seems like something reacts with the anisaldehyde and produces a colored product, but does he want more details than that?)

In general, I think the secret to a painless semester of orgo lab is to be able to write the reports efficiently and without being too time-excessive. And the secret to report-writing is to accurately predict which ideas they expect you to write about in each section (that's listed on the grading rubric that is attached to the back of our returned reports).
It's a bit unfair that they don't tell us those expectations before we write the report. (How should we know which points they think are "the most relevant"? Even different professors will have different opinions about that! )
But with a bit of thought we can easily come pretty close. In general, (1) follow the outline on the syllabus, and be sure to add (2) anything mentioned in the Postlab section at the end of every handout, (3) the announcements on blackboard (usually written by the TA who will grade that week's lab) and (4) the 10 minute in-lab intro by Cory Valdez. That intro is often similiar to the intro they want on our report, and he always shows the reaction with molecular structure, and often adds hints as to what we should write for the different sections of our report.