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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: fetusinprogress on April 02, 2008, 10:54:48 AM

Title: drawing structures
Post by: fetusinprogress on April 02, 2008, 10:54:48 AM
Could someone help me on drawing the following structures?

1) meso-3,4-dibromohexane
2)  cyclopentene oxide
3) trans-1,2-dibromopentane
4)  Z-2-phenyl-2-butene
5) meso-3,4-hexanediol
6) R-2-ethylpentanenitrile
7) acetaldehyde + propionaldehyde
 propyne + isobutylene
Title: Re: drawing structures
Post by: Arkcon on April 02, 2008, 11:20:24 AM
Yes.  I recognize their names, so I could.  Next question.  ;D




OK, jus' playin' with you, we do like to see a little effort on these boards, so take some stabs, make some drawings in a paint program and post 'em, or let us know where you're stuck.  There are always noobs who dump complete answers to any question asked, presumably for empathic brownie points.  But even they get bored quickly, and stop answering large stacks like yours.
Title: Re: drawing structures
Post by: agrobert on April 02, 2008, 11:21:45 AM
http://en.wikipedia.org/wiki/Acetaldehyde
Title: Re: drawing structures
Post by: Arkcon on April 02, 2008, 11:24:47 AM
http://en.wikipedia.org/wiki/Acetaldehyde

5 bucks says your answer earns you a "not good enough" from the original poster. ;D
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 11:43:07 AM
can you tell me how to upload from my paint program?


Title: Re: drawing structures
Post by: Borek on April 02, 2008, 11:47:11 AM
Save as gif, click on Additional options below edit field when posting.
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 11:48:42 AM
(http://img)
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 11:51:00 AM
ok here is what i have so far
Title: Re: drawing structures
Post by: Arkcon on April 02, 2008, 12:10:14 PM
For cyclopentene oxide, I like the first one better than the second one, your instincts are correct -- it's name starts with pent-, and cyclo, so you've made a circular 5 carbon ring.  Don't forget the -ene, though.  Also, you've drawn the oxygen as a carbonyl group, and compounds with those don't bear the name oxide.  If you have to guess, can you think of another common organic oxide, and look up it's structure.
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 12:28:22 PM
i looked up nitric oxide...am i lacking a bond?

Title: Re: drawing structures
Post by: Arkcon on April 02, 2008, 12:30:55 PM
i looked up nitric oxide...am i lacking a bond?

No, that's an inorganic oxide, I meant something else, made of carbon and hydrogen, with the name "oxide"
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 12:37:42 PM
I am kind of numb and feeling more confused now than when I started  :)
Title: Re: drawing structures
Post by: Borek on April 02, 2008, 12:42:04 PM
http://en.wikipedia.org/wiki/Ethylene_oxide
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 12:50:26 PM
revised...is this right
Title: Re: drawing structures
Post by: Arkcon on April 02, 2008, 01:13:49 PM
http://en.wikipedia.org/wiki/Ethylene_oxide

It was hard to find that one (or any other organic oxide)by searching for "oxide", I'm guessing that is an informal name.  But that was the molecule I was going for.
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 01:40:08 PM
so was the revised structure correctly showing cyclopentene oxide??
Title: Re: drawing structures
Post by: Arkcon on April 02, 2008, 02:01:36 PM
so was the revised structure correctly showing cyclopentene oxide??

No, I don't like the double bond to the oxygen, that is a carbonyl- group, and it gives compounds names like, -dehyde and -one, see here:
http://en.wikipedia.org/wiki/Carbonyl, also check Borek:'s link, it's where I wanted you to go, anyway.  It is quite a common industrial chemical, so you should get to know it.
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 02:12:28 PM
ok--I think I got it---

how is this!
Title: Re: drawing structures
Post by: fetusinprogress on April 02, 2008, 02:54:57 PM
would you mind looking over my other structures that i have worked on...
and thanks for your help...i do appreciate it....
Title: Re: drawing structures
Post by: AWK on April 03, 2008, 01:16:55 AM
assign names for structures
cyclopentanone
cyclopentenone
cyclopentene oxide
Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 11:06:53 AM
the bottom is cyclopentene oxide
Title: Re: drawing structures
Post by: sjb on April 03, 2008, 11:12:44 AM
the bottom is cyclopentene oxide

Unfortunately, no.

Compare how the structure of ethylene oxide (from Borek and Arkcon's prod) compares to ethylene.

What does cyclopentene have in common with ethylene, and hence what is the structure of cyclopentene oxide?
Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 12:23:20 PM
okay--i really think i may have the right idea now....

Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 12:24:47 PM
the correct structure is the one to the far right..



???
Title: Re: drawing structures
Post by: Arkcon on April 03, 2008, 12:32:27 PM
Great, now change that ethylene oxide into cyclopentene oxide -- what is the difference?
Title: Re: drawing structures
Post by: sjb on April 03, 2008, 12:34:59 PM
the correct structure is the one to the far right..



???

Bravo! :)
Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 12:36:42 PM
ethylene has 2 carbons where cyclopentene has 5
Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 12:37:51 PM
can we work on my other structures?
Title: Re: drawing structures
Post by: sjb on April 03, 2008, 12:42:33 PM
The others that you've drawn look OK too, I think.

Not sure about "trans-1,2-dibromopentane though". But that's not necessarily your fault - I can't really see how you get cis / trans forms there - have you copied the name right?

5 is essentially the same as 1, except you have -OH, not -Br. How are you doing for 6 & 7 ?
Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 12:47:43 PM
I haven't attempted to finish with 6 and 7....I will do that right now.

thank you ~!
Title: Re: drawing structures
Post by: fetusinprogress on April 03, 2008, 12:58:11 PM
here is a 2 ethylpentane...where do I attach the
nitrile
Title: Re: drawing structures
Post by: sjb on April 03, 2008, 01:22:06 PM
As it isn't mentioned, I'd put it at the 1 position, but be careful not to add an extra carbon-triple bond nitrogen there, as the carbon is already in place.

It may be easier if you start with pentanenitrile, then add an ethyl to the 2-position. It should make no difference in this case. Seehttp://www.chem.uic.edu/web1/OCOL-II/WIN/CH21/F1.HTM (http://www.chem.uic.edu/web1/OCOL-II/WIN/CH21/F1.HTM)

Are you happy assigning priorities and hence drawing the (R) form?
Title: Re: drawing structures
Post by: AWK on April 04, 2008, 02:14:41 AM
here is a 2 ethylpentane...where do I attach the
nitrile
2-ethylpentane is a nonsense name