Talk:Cyclopropane

Molecular orbitals
I'm placing this note here as a reminder to write something when I have more time.

The article needs a section on the unique molecular orbitals of cyclopropane. As a reference I have Modern Physical Organic Chemistry by Anslyn and Doherty, the most recent edition, page 850-852. Let me know if you can help write this section. Crystal whacker (talk) 09:16, 3 October 2008 (UTC)

"Pipes of small diameter" to prevent "high speed collisions between molecules" ?
This is a little confusing ... I assume what is meant is only that the small pipes and tungsten wool prevent the stuff from sloshing around quickly and striking a surface with some force? Wnt (talk) 18:08, 8 January 2010 (UTC)

Density
In the list of physical constants a density is mentioned of 1.8 at 0o and 1 atm. Being a gas (boiling at -32) I do not assume this is the density of the liquid, but for relative to air density as is rather customary for vapors, the molecule is not heavy enough. Some explanation might be needed.T.vanschaik (talk) 07:31, 23 March 2012 (UTC)
 * It clearly states that the value (1.879) is in units of g/L, so that is definitely a gas not a liquid and is an absolute measure not relative to air. DMacks (talk) 08:12, 23 March 2012 (UTC)
 * Close reading is a virtue, sorry.T.vanschaik (talk) 20:53, 24 March 2012 (UTC)

Split article to cyclopropane and cyclopropanation?
While this article has a lot of good information on the synthesis and reactivity of cyclopropanes in general, little of it is acutally to do with cyclopropane itself. I wonder if there's a case for splitting the article into cyclopropane and cyclopropanation pages? Cyclopropanation is fairly important, so I imagine it would be able to stand by itself.Project Osprey (talk) 13:18, 13 March 2013 (UTC)
 * To me, your idea of splitting is a good one. I think that the cyclopropane article should discuss cyclopropane itself and simple derivatives, cycloproanes. To some extent the current article over-emphasizes kind of specialized stuff in a graphical sense, but that's Wikipedia. But cyclopropanation methods of interest to our crowd would rarely mention cyclopropane itself.  Cyclopropanes are common in nature, so we eventually would like a biosyn section. Org Syn gives 41 hits to "cyclopropane." --Smokefoot (talk) 03:30, 14 March 2013 (UTC)
 * In that case I'll start the new pages in my sandbox. It could take a while but at least that means that anyone apposed has plenty of time to voice their views. I may need a hand implementing the finished versions (if it gets that far), changing re-directs is a mystery to me. Also, I haven't been able to find out how cyclopropane is produced industrially. Considering its instability I can't imagine that it's simply fractionated out of oil. Does Ullmann's give any hints? Project Osprey (talk) 12:53, 14 March 2013 (UTC)
 * Onw issue of 2003 Chemical Reviews is dedicated to cyclopropanes. These are still rather specialized but they might refer to a book about how cyclopropanes are prepared:

This might be a decent start. My guess is that the most commercially, societally, and synthetically important cyclopropanes are the pyrethrinoids (not that one could easily detect this aspect from the current article, which focuses seemingly on some esoterica). --Smokefoot (talk) 14:11, 16 March 2013 (UTC)
 * de Meijere, A., "Introduction:‚Äâ Cyclopropanes and Related Rings", Chemical Reviews 2003, 103, 931-932.
 * Fedory≈Ñski, M. Ç., "Syntheses of gem-Dihalocyclopropanes and Their Use in Organic Synthesis", Chemical Reviews 2003, 103, 1099-1132.
 * Lebel, H. l. n., Marcoux, J.-F. o., Molinaro, C., Charette, A. B., "Stereoselective Cyclopropanation Reactions", Chemical Reviews 2003, 103, 977-1050.
 * Pietruszka, J. r., "Synthesis and Properties of Oligocyclopropyl-Containing Natural Products and Model Compounds", Chemical Reviews 2003, 103, 1051-1070.
 * Wessjohann, L. A., Brandt, W., Thiemann, T., "Biosynthesis and Metabolism of Cyclopropane Rings in Natural Compounds", Chemical Reviews 2003, 103, 1625-1648.
 * First drafts of the new pages are ready. Cyclopropane is here and cyclopropanation is here. There's probably loads I've left out but I've done my best to put it all into some semblance of order.Project Osprey (talk) 17:19, 24 March 2013 (UTC)


 * I mostly see content destruction and duplication of content already present in other articles, not an improvement V8rik (talk) 20:37, 24 March 2013 (UTC)
 * Well, I suppose that any feedback is useful. Before I start trying to identify specific issues can I ask your opinion of the general idea here? Do you think the page should be split in this way? --Project Osprey (talk) 10:48, 25 March 2013 (UTC)
 * Probably V8rik is referring to the omission of his artwork (his term content destruction is melodramatic - difficult to destroy things here).  For these overview articles, that artwork (such as :AmideCyclopropanation.png
 * AmidecyclopropanationMechanism.png
 * Nitrocyclopropanation.png
 * MethylenecyclopropaneIsomerization.png are too narrow IMHO. One would not find these reactions in any 1-3 page overview of cyclopropane or cyclopropanation, which is what we are doing. Such art and content belong in a more specialized articles for Wikipedia and perhaps we should create articles that would accommodate those chemdraws, since they are lovely and intriguing. Or they might be listed in an appendix for super-specialist.--Smokefoot (talk) 12:43, 25 March 2013 (UTC)


 * Discussing organic reactions is always accompanied with reaction schemes or examples of a specific reaction type. What specific example to use in a text is not that relevant as long as there is an example. If you think a section of an article is too specific it can always be placed in a more specific article. Why deleting the content? If you do not like the phrase "content destruction", "deletion creep" is an alternative V8rik (talk) 22:20, 25 March 2013 (UTC)
 * Dealing specifically with the 4 images above. The first two are currently being used to illustrate the Simmons-Smith reaction, however I do not believe they are Simmons-Smith reactions (different reagents, wrong substrate). If anything, they seem to show cyclopropanation using a modified Tebbe's reagent. Either way I thought the mechanism for the 'classic' reaction would be more useful. I feel less strongly about the other 2 images. For the section on free carbenes, I replaced the third image to one showing dihalocarbenes, as these are a bit more common than carbenes generated from bromo-nitromethane (they have a nice review article), but realistically there's no reason we can't have both. Not fussed at all about re-introducing the final image. Project Osprey (talk) 01:12, 26 March 2013 (UTC)
 * I agree with Osprey's assessment, especially that Simmons Smith is mainly Zn chem. The second scheme is speculative and of interest to a cutting edge research scholar.  I am not expert enough about the third scheme but my impression is that dihalocarbene additions are similar and far more common.   The fourth scheme is too tangential.  Perhaps we should start up methylenecyclopropane to accommodate it.  Here is an OS lead [] and here is a review  http://onlinelibrary.wiley.com/doi/10.1002/1615-4169(200202)344:2%3C111::AID-ADSC111%3E3.0.CO;2-0/abstract.--Smokefoot (talk) 13:42, 26 March 2013 (UTC)
 * I've done what I can to preserve content by moving some of the more specialist stuff to specific pages where it has more relevance (best compromise I can think of). I'll perform the split later today unless anyone has any more objections? Project Osprey (talk) 14:03, 31 March 2013 (UTC)