Retrosynthesis and Liquid-Liquid Extraction: Crash Course Organic Chemistry #34

As we construct more complex organic molecules, it can start to feel like decrypting a complex code. Organic synthesis takes simple starting materials, and turns them into complex structures, and reverse engineering can help us figure out the steps in between. In this episode of Crash Course Organic Chemistry, we’ll practice multistep synthesis problems, learn about how we can use retro synthesis to make more complex molecules, and use liquid-liquid extraction to separate solvents. As always, we’ll work through examples and connect everything back to our Mold Medicine Map!

Music:
Plucky Daisy by Kevin MacLeod

Series Penicillin References:
Nicolaou, K. C., & Sorensen, E. J. (1996). Classics in total synthesis: targets, strategies, methods. John Wiley & Sons.
Sheehan, J. C. (1982). The enchanted ring: the untold story of penicillin.
Primary literature for Sheehan’s penicillin synthesis: Sheehan, J.C. & Izzo, P.T. J. Am. Chem. Soc. 1948, 70, 1985; Sheehan, J.C. & Izzo, P.T. J. Am. Chem. Soc. 1949, 71, 4059; Sheehan, J.C. & Bose A.K. J. Am. Chem. Soc. 1950, 72, 5158; Sheehan, J.C., Buhle, E.L, Corey E.J., Laubach, G.D. & Ryan J.J. J. Am. Chem. Soc. 1950, 72, 3828; Sheehan, J.C. & Laubach, G.D. J. Am. Chem. Soc. 1951, 73, 4376; Sheehan, J.C. & Hoff, D.R. J. Am. Chem. Soc. 1957, 79, 237; Sheehan, J.C. & Corey E.J. J. Am. Chem. Soc. 1951, 73, 4756

Series Sources:
Brown, W. H., Iverson, B. L., Ansyln, E. V., Foote, C., Organic Chemistry; 8th ed.; Cengage Learning, Boston, 2018.
Bruice, P. Y., Organic Chemistry, 7th ed.; Pearson Education, Inc., United States, 2014.
Clayden, J., Greeves, N., Warren., S., Organic Chemistry, 2nd ed.; Oxford University Press, New York, 2012.
Jones Jr., M.; Fleming, S. A., Organic Chemistry, 5th ed.; W. W. Norton & Company, New York, 2014.
Klein., D., Organic Chemistry; 1st ed.; John Wiley & Sons, United States, 2012.
Louden M., Organic Chemistry; 5th ed.; Roberts and Company Publishers, Colorado, 2009.
McMurry, J., Organic Chemistry, 9th ed.; Cengage Learning, Boston, 2016.
Smith, J. G., Organic chemistry; 6th ed.; McGraw-Hill Education, New York, 2020.
Wade., L. G., Organic Chemistry; 8th ed.; Pearson Education, Inc., United States, 2013.

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Want to find Crash Course elsewhere on the internet?

[kjjk]

Oh, so this is what it feels like for Crash Course to upload exactly what you need exactly when you need it!

[nicholassummerlee]

This is an amazing video. Orgo is just one of those classes that breaks your soul. I’m happy that I still understood 80% of what the video was teaching.

[zeem]

Imagine if CC didn’t exist...many students would fail their exams.
Thanks Crash Course ❤️❤️❤️

[Warrentheo]

This just got suggested by YouTube, first video in this series that I have seen... Apparently I need to start at the beginning, because I understood maybe the words 'change' and 'bond', everything else was a garbled mess... lol

[quimicasg]

Great to hear from Deboki Chakravarty Again!
I think not only organic chemistry, she should teach all the chemistry in and out of the science textbooks...
This channels selective chemistry vids are very good..
:)

[twothreebravo]

7:33 It only took 34 episodes for Deboki to actually DO some chemistry! ;)

[HexLabz]

Oh, hey! Crash course is doing chemistry now. Maybe it will help me make sense of the college course I barely made it through, and... nope. Already in the fetal position.

[karlbergen]

I took organic chemistry some years ago at a university. I don't ever remember being taught this concept.

[skylegendmemesofficial]

I didn't understand anything but I Love this tutor

[ΕυάγγελοςΠαπαγγελής]

4:20 actually the number of carbon atoms on the starting molecule is 15...i think tou missed the two ethyl groups on the amide group

[cheesemons]

My brain hurts so hard during the last few minutes of the video

[benscrafield]

There’s some slightly strange reasoning here. First of all, you can’t just say that when a starting material and a product both have the same absolute configuration label, you must have overall retention: CIP priority means that you can invert a stereocentre with a lower priority group to get a product with the same R or S label. Then, in the retrosynthesis, there was no real discussion of which bonds to break beyond “we’ll break these bonds because we’ve covered this chemistry.” Even if, as a chemist, you don’t know how to make a particular bond, it is your due diligence to look up the possibility of the alternative disconnection if your route is not especially concise (like the one in the video). Perhaps aldol chemistry hasn’t been covered in this series yet, but it is one of the most classical kinds of C-C disconnection, and would be equally applicable here.

[joshualeft]

pretty sure you guys forgot about Alan Turings existence

[ashfaqmaster]

How come PBr make a bond mam?? Is it possible to make a halide of PBr??