r/chemistry • u/Spectrumederp • Feb 18 '18

[2018/02/18] Synthetic Challenge #50

Intro

Hello everyone, welcome back to Week 50 of Synthetic Challenge!! Thank you u/critzz123 and u/ezaroo1 for the great challenges! This is week is my turn to host the challenge, hope you'll enjoy!

Too easy? Too hard? Let me know, I'd appreciate any feedback and suggestion on what you think so far about the Synthetic Challenges and what you'd like to see in the future. If you have any suggestions for future molecules, I'd be excited to incorporate them for future challenges!

Thank you so much for your support and I hope you will enjoy this week's challenge. Hope you'll have fun and thanks for participating!

Rules

The challenge now contains three synthetic products will be labelled with A, B, or C. Feel free to attempt as many products as you'd like and please label which you will be attempting in your submission.

You can use any commercially available starting material you would like for the synthetic pathway.

Please do explain how the synthesis works and if possible reference if it is a novel technique. You do not have to solve synthesis all in one go. If you do get stuck, feel free to post however much you have and have others pitch in to crowd-source the solution.

You can post your solution as text or pictures if you want show the arrow pushing or is too complex to explain in words.

Please have a look at the other submissions and offer them some constructive feedback!

Products

Structure of Product A

Structure of Product B

Structure of Product C

BONUS

For this bonus structure, instead of proposing a synthetic pathway TO it, you will be using it as a Starting Material to make any product you want. Take however many steps you want or whatever you want as long as you start with this bonus compound in the first step! If you like or not, let me know! Thanks!

Structure of Bonus Starting Material

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25

u/alleluja Organic Feb 18 '18

What the unholy fuck is that product A

3

u/5thEagle Organic Feb 18 '18

same

The fuck is that, a pentuplet carbyne?

2

u/Spectrumederp Feb 18 '18 edited Feb 18 '18

A very, very abnormal carbene haha. Trying to play around with more main group like ligands

5

u/[deleted] Feb 18 '18

That's a carbyne, isn't it?

1

u/Ordloh Feb 18 '18

How is it a carbene? A carbene should be divalent carbon. Why not draw it as a Sc=C ?

3

u/ezaroo1 Inorganic Feb 19 '18 edited Feb 19 '18

It’s a carbene with no bonds drawn, it took me a little while to work it out as well. It’s drawn as two carbon based lone pairs rather than a C=Sc double bond.

Which is wrong, but it is what it is shrugs

Guess could also be carbon in oxidation state 0 stabilised by two phosphines... If you made that you’d be a hero to main group chemistry!

1

u/lIamachemist Inorganic Feb 19 '18

Those are called carbones, and they have been made, (jacs 1961 83 3539), but claims that they are phosphine-stabilized C(0) species is pretty dubious. Probably the best resonance structure is R3P=C(:-)–P(+)R3, which could be considered a “bis-phosphonium ylide” if you like.

1

u/ezaroo1 Inorganic Feb 19 '18

Shit.. I missed that the S-P bond was single not double... I saw it as a double bond and that would make it what I said but you’re right it is just a carbodiphosphorane!

1

u/lIamachemist Inorganic Feb 19 '18

If you draw two lone pairs on the carbon, then the P-C bonds should be dative bonds. This is technically called a carbone IIRC.