Talk:Aldol reaction/Archive 1

message: This article is terrible.  It needs a lot of work.  The aldol reaction isn't very useful?!?  Eugene Kwan 07:27, 15 December 2005 (UTC)
replies: text: I agree that this article is terrible and needs tons of work.  I'll help out fixing it. ~K 15:47, 15 December 2005 (UTC)
thread_title:  Quality of Article 

message: I caught some errors in section entitled Crossed aldol reaction.  I've reworked it and entitled the section Enolate formation.  Please double check my work. ~K 04:41, 16 December 2005 (UTC)
replies: text: Thanks for the tips, and good point about the MeMgBr.  I remember it being more basic than nucleophilic, but I think I should remove that statement just to be sure.  And, of course, there is tons more to write.  You're clearly the expert on this subject.  Why don't you write a little? ~K 07:36, 16 December 2005 (UTC)
thread_title: Crossed aldol section

message: Can someone please find the original 1872 references from Wurtz and Borodin?  I can't seem to find them. ~K 18:18, 17 December 2005 (UTC)
replies: text: I found the Wurtz reference.  Still looking for the Borodin reference. ~K 23:48, 17 December 2005 (UTC)
thread_title:  Original references 

message: I've left in some empty sections to organize myself...I plan to work on this again soon.  I hope this isn't against the rules...  Anyone think we can get this page into the Featured Articles?  That'd be so cool.  Of course, it needs a ton of work before it's ready for that. Eugene Kwan 00:02, 18 December 2005 (UTC)
replies: text: I was also thinking that this would be a good first chemical reaction featured article.  It's a long road to a FA, but if we stick with it we can do it. When we are finished with the page, we'll submit it for peer review, and after that we'll submit it for FA status. ~K 00:28, 18 December 2005 (UTC)
replies: text: Just to piggyback on here, where there's a decent chance of finding a chemist (!) we have an iodine clock reaction and Old Nassau reaction article but no general article on clock reactions. I'm hoping someone here might be inspired, once you're done with this article, of course! - Nunh-huh 00:31, 18 December 2005 (UTC)
replies: text: Make this request to the Wikiproject Chemistry.  I'm sure someone there can help you with this. ~K 00:45, 18 December 2005 (UTC)
replies: text: Wow! I didn't know we had one! Thanks. - Nunh-huh 02:21, 18 December 2005 (UTC)
thread_title:  Work in Progress 

message: I've added lots in the stereoselectivity section...any comments?  Maybe someone can do the thermo vs. kinetic enolate bit in the previous section.  Eugene Kwan 03:29, 19 December 2005 (UTC)
thread_title:  Comments 

message: Nature disputes the accuracy of this article; see http://www.nature.com/news/2005/051212/multimedia/438900a_m1.html and Wikipedia:External_peer_review#Nature.  We're hoping they will provide a list of the alleged errors soon. —Steven G. Johnson 01:46, 15 December 2005 (UTC)
replies: text: Nature will shortly be releasing a list of errors (or something equivalent). I think that the idea is we'll wait till then, make sure we've addressed any valid points, and then take the tag down. - Nunh-huh 03:54, 20 December 2005 (UTC)

text: I believe the errors found by Nature have been corrected.  Could someone please verify this? ~K 03:28, 23 December 2005 (UTC)

text: Agree with Eugene above. LDA is not really that hard to handle and liquid N2 is dirty cheap. I think the article looks quite impresive now. After those empty sections are filled I think it would easily pass FAC. -- Rune Welsh | ταλκ | Esperanza 13:44, 25 December 2005 (UTC)
replies: text: I completely agree with the Nature reviewer on all counts.  Under the traditional aldol conditions of NaOR in ROH as base all steps are reversible (the dehydration step is much less so). Our page should show that, this type of method is still widely used. Indeed the standard lab prep of dibenzalacetone from acetone and benzaldehyde (see Williamson's lab text) is done in water with NaOH as catalyst – clearly the enolate is formed reversibly.  I agree that low temperature LDA work is "avoided" is wrong; I was involved in making a 400 L batch of LDA in 1983 (we made an enolate at well above -78 C), and my old company (after 1987) had a plant capable of running -78 C reactions routinely on 400 L scale and larger.  Dry ice is routinely used in many chemistry labs. Walkerma 20:57, 28 December 2005 (UTC)

text: I agree with the above statement about the traditional base-catalyzed aldol conditions: all the intermediates and products are in equilibrium.  However, when using "kinetic conditions" with preformed enolates there is no (or very little) equilibrium.  We should mention this. (P.S. The thought of working with 400L of LDA scares me. :) ) ~K 02:52, 29 December 2005 (UTC)
thread_title:  Nature errors to correct 

message: Would someone mind checking over the stereochemical models I've put in...you know, for absolute stereochemistry, consistency, and general sense?  I think it's all correct, but with so many stereocenters...  I'm debating how to do the rest of the article...any sections that should be added/deleted/expanded? Eugene Kwan 22:16, 25 December 2005 (UTC)
replies: text: Eugene, your doing a great job.  Keep on going!  When you're done, alot of people will probably rewrite alot of what you've written, but you shouldn't take that the wrong way.  We're all chipping in to make the article better.  Right now, you're our "resident expert", and you've given the article much needed direction and content.  I look forward to what comes next. ~K 02:41, 29 December 2005 (UTC)
replies: text: Let me second that.  When this is done it will be better than Britannica by far! I won't review the stereochemistry till I get home and can check things in March etc. Walkerma 03:08, 29 December 2005 (UTC)
thread_title:  Stereochemical Models 

message: I've added a lot of stuff on the Evan's aldol.  I'm going to add some stuff on the catalytic, asymmetric methods available, and give an example or two in total synthesis, and then that'll probably be the bulk of my contributions...  As always, your feedback is appreciated.  Eugene Kwan 23:55, 1 January 2006 (UTC)
thread_title:  Evans Aldol 

message: Hi everyone, not to be a bother or anything, but do you think we might stick to a common chemical structure format?  I've been using the ACS template with no explicit hydrogens unless necessary...  Also, do you think the intro scheme and the enol/enolate scheme I put in are sort of similar?  Eugene Kwan 05:22, 5 January 2006 (UTC)
replies: text: Hi Eugene.  Yes, your scheme and mine are quite similar, I plagiarised yours shamelessly! I hope that on Friday to post a rewrite of that section so the duplication will disappear, but I don't think it's a serious problem for a temporary situation as there are significant differences.  I wanted to get the intro up fairly quickly. As for format, I think your format is the right one for the bulk of the article, but for the intro I think it's better to include hydrogens.  Many undergraduates have a hard time understanding line-angle formula; for this reason most textbooks (such as Wade that I cite) show hydrogens explicitly when explaining the basics, but they use line-angle in many questions & examples.  Is it a problem to do our schemes like in Wade?  I think the only other scheme I plan to revise is the mechanism scheme, which I plan to break into two parts as I want to describe the mechanisms explicitly.  By the way, I loved your definition of the aldol; I struggled with this for a while for the intro, then noticed yours in the text that followed, better than anything I could think of! Walkerma 06:28, 5 January 2006 (UTC)

text: I did that a while ago. ~K 04:24, 6 January 2006 (UTC)
thread_title:  Common Format 

message: I am working on mechanism schemes (offline, in ACS format Eugene!), trying to tie things in with the later article.  We show propiophenone and acetophenone reacting to give an aldol product, but based on what I know of ketone equilibria and aldol thermodynamics this reaction is unlikely to go to any significant extent.  Am I wrong (maybe because of the aryl group)?  Or should we consider having two aldehydes for the crossed aldol example? Wade uses acetaldehyde and propionaldehyde, this example is often used I think. Please let me know your thoughts, thanks, Walkerma 07:04, 6 January 2006 (UTC)
thread_title:  Question on example used 

message: I removed part of the end of 5.1 Evans' Oxazolidone Chemistry which discusses stereoselective β-hydroxyketone reduction.  It was off-topic, and as the section was getting longish, it seemed a good way to trim the article.  However, if others feel I'm wrong, the text is still in the database and can easily be put back in the article. ~K 21:22, 7 January 2006 (UTC)
replies: text: I see what you're saying.  I think if you put that clarification in the article, then knuckleheads like me would follow you better. ~K 05:43, 8 January 2006 (UTC)
thread_title:  Evans' chiral oxazolidone edit 

message: "The aldol reaction is an important carbon-carbon bond forming reaction in organic chemistry[1][2]"
Importance is inherently subjective.  If the cited articles claim that the reaction is important, the article should make it more clear that the opinion (as well as the fact that the reaction is a carbon-carbon bond forming reaction in organic chemistry) comes from the articles.  However, I suspect it would be far better to rework the sentence/paragraph to show that the reaction is important, rather than saying that the reaction is important.  --Dfeuer 02:11, 25 January 2006 (UTC)
replies: text: This is not simply an opinion!  One can check the references, which confirm that the reaction is indeed important, based on the fact that at both the basic level (Wade) and the more advanced level (March) a lengthy description is given for the reaction and its uses (March gives 58 references).  Moreover, this type of introduction is a standard style used in chemistry. Finally, the fact that Nature chose to review this topic is also an indication of its importance.  Walkerma 20:33, 25 January 2006 (UTC)
thread_title:  NPOV 

message: The 'matched case' and 'mismatched case' show the same aldehyde, though the transition states are drawn with their enantiomers. (Presumably, the enantiomer of the 'matched case' aldehyde should be shown.) The referenced JACS article (1995, 117, 9073) does not contain the reaction in the image, although it is similar.
Yes, I thought I had explained that, but I think I might have left it out.  The real reaction done is with the same aldehyde, but to show the model more clearly, I drew the enantiomer of the aldehyde.  As for where the reaction came from, I got it from the Chem 206 notes (www.courses.fas.harvard.edu/~chem206; Aldol lecture 2), and I just put in the reference that was given.  I'm a little puzzled as to where that example is from now.  Suggestions?  Eugene Kwan 01:04, 22 February 2006 (UTC)
thread_title:  Errors in the 'Matched/Mismatched' section 

message: I took a picture today of my aldol reaction.  I'm not sure how you make it smaller, so please, reformat, reformat!  Thanks.  Eugene Kwan 20:13, 28 February 2006 (UTC)
replies: text: Sorry I missed the caption.  I have moved it now.  There's quite a bit of whitespace right now (at least in my browser) so maybe things need to be shuffled around a bit. Edgar181 20:53, 28 February 2006 (UTC)
thread_title:  New Picture 

message: Hey guys, I have a little time to work on this article again...I'm open for suggestions.  I was going to add a bit on the newer organocatalytic and catalytic, asymmetric methods, plus some stuff on thiazolodinethione auxiliaries.  Any ideas?  It's a pretty big article already.  What do we need to do to get it to "featured article" level? Eugene Kwan 16:30, 24 November 2006 (UTC)
replies: text: * This reaction is a standard part of the second-semester syllabus in most US introductory undergraduate organic chem courses, so probably many thousands of students check this page (mostly around April, when it is usually taught).  These students should know the basics of organic chemistry, including basic carbonyl chemistry, but many will probably be unfamiliar with terms like regiochemistry, stereoselectivity, asymmetric induction, kinetic vs. thermodynamic products.  They should hear in class about use LDA and alkoxide bases (no others!), dehydration, and the problem of control in crossed aldols.  In the UK it's probably similar, but may go a little deeper (e.g. kinetic vs thermodynamic enolates).  I also cover the reaction in more detail in my advanced organic class - a much smaller number of students take this - and for that course the more advanced coverage in this article (E/Z enolates, Evans, etc.) is excellent. I hope this provides some guidance on what I'd guess the "average" reader of this page could be expected to know. Walkerma 06:22, 26 November 2006 (UTC)
thread_title:  Revisions 

message: I would vote for 
:The aldol reaction is an important method for forming carbon-carbon bonds
instead of "constructing". One constructs the skeleton of a molecule, or perhaps even the stereochemistry around a particularly difficult center, but a simple carbon-carbon bond is just "formed".
Also, I'm not really in favor or "naturally occurring molecules". "Natural products" is what the total synthesis folks synthesize, and using any other word is imprecise language and talking down to the readership. They deserve better. Dr Zak 22:09, 7 December 2006 (UTC)
replies: text: I agree, especially with using forming instead of constructing. These are always called bond formation reactions in my experience. Maybe the idea was to avoid the funny-sounding "for forming", but that could be avoided by rephrasing. Maybe "The aldol reaction is an important carbon-carbon bond formation reaction", or "The aldol reaction is an important method for the formation of carbon-carbon bonds". Itub 23:34, 7 December 2006 (UTC)
replies: text: OK, agreed.  I just thought the ordinary person would not have the terms "natural product" or "bond formation" in their vocabulary.  It's a tough job.  What's the FA status?  Will it just sit on the FA nominees list forever?  Also, I felt thalidomide was a bad example, since the enantiomers interconvert in the body. Eugene Kwan 03:36, 8 December 2006 (UTC)
replies: text: Amen, brother, on the thalidomide. Plus it's not an aldol adduct either. By the way, shouldn't it read "multigram-scale quantities of the drug" near the end of the first paragraph? Dr Zak 03:43, 8 December 2006 (UTC)

text:  Yes, that works too. Eugene Kwan 00:06, 9 December 2006 (UTC)
thread_title:  Introduction 

message: The following sentence appears in the Organocatalysis section: "A more recent[when?] development is the use of chiral secondary amine catalysts. These secondary amines form transient enamines when exposed to ketones, which may react enantioselectively[48] with suitable aldehyde electrophiles." The question [when?] was asked correctly by someone, and it has not been answered as yet (1.10.2014). Ref.48 points to a contribution by Carreira, E.M. et al. in the year 2006. Is it possible that this [2006] is the answer? Only the contributor adding the above lines can help. Zghajos
User:Zghajos
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Remarks to the Wikipedia Organocatalytic aldol reactions
Zoltan G. Hajos zghajos(AT)t-online.hu
The reaction scheme (a) as shown in the Wikipedia Organocatalytic aldol reactions page has only been described in the Hajos, Parrish Patent (b) and the Hajos, Parrish paper (c).
Since Hajos and Parrish worked at ambient temperature using a catalytic amount (3% molar equiv.) of (S)-(-)-proline they could isolate the optically active intermediate bicyclic ketols a prerequisite of elucidating the reaction mechanism. This was most likely the reason for Professor Claude Agami to call the reaction the Hajos-Parrish reaction in his paper in J.Chem.Soc., Chemical Commun., 1985, 441-442 (d).
The Hajos, Parrish Patent (b) also described the Asymmetric synthesis utilizing (S)-(-)-proline even in the absence of added solvent.
The last few lines of the Hajos, Parrish 1974 paper read: "We believe our results may be considered an example of a simplified model of a biological system in which (S)-(-)-proline plays the role of an enzyme." This has been referred in a publication by Mohammad Movassaghi and Eric N. Jacobsen of the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA: The Simplest "Enzyme" Science, 6 December 2002, Vol. 298, 1904-1905 (e).
The above is also described in the Benjamin List Tetrahedron report number 613 in 2002 (f). This Tetrahedron report shows that the Schering group executed the reaction under non biological conditions using (S)-Proline (47 mol%), 1N perchloric acid, in acetonitrile at 80 degrees C. Hence, they could not isolate the Hajos, Parrish intermediate bicyclic ketols. The original 1985 naming of the reaction by Claude Agami (d) has been expanded in this 2002 paper (f) by adding three more names of the Schering group.
References to the Zoltan G. Hajos Remarks. a.http://upload.wikimedia.org/wikipedia/commons/d/de/Organocatalytic1.gif]
b. Hajos, Z, G.; Parrish, D. R. Asymmetric Synthesis of Optically Active Polycyclic Organic Compunds. German Patent DE 2102623, July 29, 1971.
c. Hajos, Z. G.; Parrish, D. R. J. Org. Chem. 1974,39,1615.
d. Agami, C.; Levisalles, J.; Puchot, C. J. Chem. Soc., Chem. Commun. 1985, 8, 441-442. 
e. Movassaghi, M.; Jacobsen, E. N., Science, 2002, 298, 1904-1905. 
f. List, B, Tetrahedron 2002, 58, 5573-5590  references 12  and 13 
The above was posted by User:Zghajos (15:55 UTC, 5 February 2007) and moved here later that day by User:Walkerma, for discussion.  Walkerma 16:49, 5 February 2007 (UTC)
replies: text: (Edit conflict) OK, I'm at work so can't comment more, but how should we incorporate this information into the article?  Dr. Hajos has graciously given us some helpful refs on the reaction that bears his name, I suggest we try to review this to decide how best to incorporate the key parts of it in an "encyclopedic" way.  Eugene, K, and others, what do you think? (I see Eugene has already commented!) Walkerma 16:59, 5 February 2007 (UTC)

text: This article may shed some light on the history - which is obviously important for the naming.  I plan to order the Angewandte article so I can look at it; U. Eder, G. Sauer, R. Wiechert, Angew. Chem. Int. Ed. 1971, 10, 496. DOI.  Since both works (the other being the Hajos patent) came out in 1971, we need to look more closely at this, I think. Walkerma 16:13, 8 February 2007 (UTC)
replies: text: I don't know the history, but I believe that the current version of the article is correct in saying "This is commonly referred to as the Hajos-Parrish-Eder-Sauer-Wiechert reaction", because that is the only way I've seen people refer to this reaction. Itub 16:24, 8 February 2007 (UTC)
thread_title:  Organocatalysis 

message: "In the section of  "the Stereoselectivity: Alpha stereocenter on the
enolate," there are figures for Z and E enolates right underneath the
description "In the case of an E enolate, the dominant control element is
allylic 1,3-strain whereas in the case of a Z enolate, the dominant control
element is the avoidance of 1,3-diaxial interactions. The general model is
presented below:"    I believe the structure for Z enolate is correct, but I
think your E enolate structure is false, as you notice both of your E and Z
are the same. Please let me know, because it doesn't really make sense
otherwise."
Well above my head, please review and fix if necessary.  Thanks, Guy (Help!) 17:56, 5 May 2007 (UTC)
thread_title:  Comment from [[WP:OTRS|OTRS]] 

message: As the editors of this article have produced an example of what I would say can fairly be called a complex article, could I ask for input on the issues of complex articles and "introduction to" articles at Wikipedia talk:Featured article candidates/Introduction to general relativity? I mention this article down near the bottom of that talk page, and list a series of "introduction to" articles. Thanks. Carcharoth 00:23, 15 July 2007 (UTC)
replies: text: "Made sure"?  Line 2 of this article is "In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hydroxy ketone, or "aldol" (aldehyde + alcohol), a structural unit found in many naturally occurring molecules and pharmaceuticals."  Tempshill (talk) 23:32, 13 February 2009 (UTC)
replies: text:  I have updated line 2 with relevant links. Basically you need to have an understanding of chemical reaction, carbon-carbon bond nucleophilic addition, ketone, aldehyde and enolate  before you can fully appreciate this article V8rik (talk) 21:01, 14 February 2009 (UTC)

text: I wasn't complaining, merely pointing out that to a layman, the article is baffling and incomprehensible; let's not have any illusions that this article is otherwise.  It's unfortunate but I'll shrug and believe you when you say it's impossible to write anything on the subject that is understandable to the layman.  I do think it goes overboard and ought to be half the current size, but then I'm just skimming it.  Tempshill (talk) 01:34, 15 February 2009 (UTC)
thread_title:  Complex articles and introduction articles - input requested 

message: How to add a footnote:
 NOTE: Footnotes in this article use names, not numbers. Please see Wikipedia:Footnotes for details.
# Assign your footnote a unique name, for example TheSun_Dec9.
# Add the macro to the body of the article, where you want the new footnote.
# Take note of the name of the footnote that immediately precedes yours in the article body.
# Add # to the footnote numbered-list, immediately below the footnote you noted in step 3. No need to re-number anything!
# Multiple footnotes to the same reference: see Wikipedia:Footnotes for a how-to, if you do not succeed by simply following the pattern.
Does this apply to old-style footnotes?--SallyForth123 20:31, 30 July 2007 (UTC)
replies: text: Sorry changed your eddit to make it better readable--Stone (talk) 12:06, 2 March 2008 (UTC)
thread_title:  Footnote lecture 

message: hi,
how about adding a comment stating that the SYN or ANTI diastereoselectivity involve RACEMIC product mixtures?
see: http://www.chem.usyd.edu.au/~mcerlean/CHEM3115Lecture4.pdf
I think this keyword is key for making this article more "complete", or helpful.
--Koala Paw (talk) 17:52, 11 March 2008 (UTC)
thread_title:  RACEMIC (+/-) mixture 

message: hi.
What is good:
* The two key examples / reactions for cis & trans boron enolates are given.
* The antiperiplanarity drawing.
I would add:
* Deprotonation is _NOT_ through a chair transition-state.
* elucidate the transition-state further, eg with two supplemental drawings for two said reactions:
** free rotation about (CO)-CH2Me bond, and the orientation of the methyl DEPENDS on whether the base OR the boron ligand is the BULKY candidate...
--Koala Paw (talk) 23:06, 16 March 2008 (UTC)
thread_title:  boron enolate 

message: Or maybe I am just ignorant.
My question is at .
Any advice / comments (or: answers!) will be appreciated. Mike Schwartz (talk) 20:31, 15 August 2008 (UTC)
thread_title:  possible typo? 

message: User Eugene Kwan as well as I use our real names, and use our expertise in our discussions. Could it not be made mandatory for contributors of Wikipedia to reveal their real names and qualifications the way Dr. Kwan and myself have done? To be more explicit: what gives the right to a person associated with Wikipedia to delete an article unless it is a hoax or it is offensive to a person or to a group of people? Does an administrator working for Wikipedia have the same positive feeling that Dr.Kwan or myself had when we accomplished something in the laboratory? In other words: it is always easier to destroy than to create.  Zoltan G. Hajos.Zghajos (talk) 03:48, 3 October 2008 (UTC)
replies: text: I don' know what this has to do specifically with the Aldol reaction article and it sounds like it involves issues far larger than just this page. On its face, it looks like User:Zghajos's concern about his edits, so let's take it to User talk:Zghajos. DMacks (talk) 05:24, 3 October 2008 (UTC)
thread_title:  Concerning Wikipedia policy 

message: This article does not have a proper separation of the lead from the body of the article. Many things mentioned in the lead such as the history of its discovery are not mentioned again.  It would not be rated GA under current standards.--Grahame (talk) 03:23, 15 February 2009 (UTC)
replies: text: I don't understand your first comment; the lead is separated from the rest of the article by the table of contents, as it is in all of the recent featured articles on the main page.  This lead is long, but if I recall correctly, that was because of requests made at FAC.  I agree, though, that a short history section in the main body would be a good idea. Thanks, Walkerma (talk) 03:32, 15 February 2009 (UTC)
replies: text: I'm just saying that the lead should be a short concise summary of the article, not separate material: "Significant information should not appear in the lead if it is not covered in the remainder of the article, although specific facts, such as birthdates, titles, or scientific designations will often appear in the lead only, as may certain quotations. This should not be taken to exclude information from the lead, but to include it in both the lead and body: in a well-constructed article, the relative emphasis given to information in the lead will be reflected in the rest of the text." (Wikipedia:Lead section#Relative emphasis).--Grahame (talk) 03:42, 15 February 2009 (UTC)
thread_title: Lead

message: Hello,
I realise that this is a highly technical article, but this is not really accessible to anyone without a bachelors in organic chemistry (or equivalent). Even the first few sentences are tough work:
 In its usual form, it involves the nucleophilic addition of a ketone enolate to an aldehyde to form a β-hydroxy ketone, or
 "aldol"  (aldehyde + alcohol), a structural unit found in many naturally occurring molecules and pharmaceuticals.[4][5][6] 
 Sometimes, the aldol addition product loses a molecule of water during the reaction to form an α,β-unsaturated ketone. 
I am not averse to technical content but as a featured article it should represent something that is, at least in the lede, accessible to the reader who is not familiar with the entire topic area. Obviously this is far more difficult a task than for music, video games, sports and other non-technical articles. User A1 (talk) 06:05, 15 February 2009 (UTC)
replies: text: Hi, I'm a high school student, and this article is readily accessible to me. I believe that this is a very well written article, and serves as a useful technical resource. 59.92.94.245 (talk) 07:07, 15 February 2009 (UTC)
thread_title:  Tehcnical detail 

message: Clearly this subject can be difficult for the uninitiated - I think that organic chemistry is probably one of the more fearsome courses of the undergraduate curriculum.  Still, there are some things that might be done to make this article a little clearer to the novice.
* Omitted hydrogens. The first reaction on the page does not show the hydrogens on the carbon atoms in the product, but does show them in the reactants (where they occur on a double bond and as an aldehyde).  This is undeniably the standard representation, but you're showing people a reaction that appears to create one single product, in an article that eventually is going to spend a great deal of time on enantiomers and stereoselectivity.  I can picture a novice staring at the reaction and thinking that H2 is eliminated when the new bond is formed.  It would be best to clarify this graphical issue at the beginning, though it may be difficult to do so concisely.
* Animation.  It would be some work, but it shouldn't be extraordinarily difficult to produce an animation sequence showing how the reaction progresses.  (see RasMol and Cn3D for example, though prettier results can be obtained with proprietary programs)  But if someone has such a graphic already made, all Wikipedia would greatly appreciate the donation... especially since I'd worry that even if I did prepare a crude sequence myself it would be ruled out as "WP:original research", since I might (not implausibly) have inaccurately portrayed some aspect of the mechanism.
* "Typical" reaction.  While some of the later graphics show more general reactions, the article starts off using a "typical" reaction that includes some distracting features (Ph, Li).  The newcomer then has to figure out which parts of the reaction are important and which to ignore.
* Better introduction of stereoselectivity.  The section on stereoselectivity begins by introducing syn and anti, (E) and (Z).  But these are issues of notation not directly relevant to this article.  Later on it is explained that "Modern organic syntheses now require the synthesis of compounds in enantiopure form.  Since the aldol addition reaction creates two new stereocenters, up to four stereoisomers may result." - but this is under the "Evans' oxazolidinone chemistry" subheading, later in the article.  Nowhere do we explain to the novice that a stereocenter (for practical purposes) is just a carbon with four ligands no two of which are identical, because any fewer can lie in a flat plane and be a mirror image of themselves, and any identical groups can be swapped to form a mirror image.  I think we should have the marking of the stereocenters all the way up in the first graphic in the lead, and the lead should summarize a little bit of the stereochemistry.  For simplicity we should stick to just one way of describing the chirality and use it consistently throughout this article, noting only that a different notation exists as described in another article.  (Also note that the first quoted sentence is technically unsourced, though it isn't hard to find references e.g. ,)
* Antibonding. The pi* orbital is mentioned, but not Wikilinked, and the role of antibonding orbitals in the transition is not explained.  There is a simpler way to describe that orientation - when a double bond forms, the ligands at either end need to be lined up in a plane rather than being twisted at some angle (which double bonds don't do).  If the antibonding orbital is mentioned at all, it should be described in more detail.
Despite these comments I don't mean to be critical of anyone for putting together this article, which really is very instructive.  Many great chemists have written organic chemistry textbooks, but has anyone written one that can easily be understood?  Still, Wikipedia is not paper, and it should be determined by experiment whether the hypertext format makes it possible to teach difficult topics more effectively than printed source. Mike Serfas (talk) 09:37, 15 February 2009 (UTC)
thread_title:  Instructional aids 

message: See headline. --87.78.34.91 (talk) 14:51, 15 February 2009 (UTC)
replies: text: First picture needs lots of things...removal of some descriptive text (along with adding description in a caption), converting to a better format (higher-resolution png or even better svg), removal of redundant parts (the second line can just redraw the aldol-reaction product from the first line instead of redoing that chemical step). I'm headed out, but can work on it in a few hours. DMacks (talk) 15:55, 15 February 2009 (UTC)

text: Notice that only the second step of the second line is called the condensation. That's another problem:) But "step 1 is called A, step 1+2 is called B" could still be written without repeating step 1...just say what each thing is and more clearly illustrating how one name is just the first step of a two-step (with different overall name) rather than two distinct things. Like the "ENOL mode" of the first diagram of the Mechanism section. DMacks (talk) 18:25, 16 February 2009 (UTC)
thread_title:  first picture missing description 

message: This new section is a good idea, but there doesn't seem to be very much actual information there.  Perhaps it should wait until an expert can come along and write something more detailed. Eugene Kwan (talk) 00:50, 5 March 2009 (UTC)
thread_title:  Biological Aldol Reactions 

message: I thought the lead was disorganized and people complained it didn't make a lot of sense before, so I took another stab at it.  Fire away.  It's probably still too technical, but I don't have a good sense for what needs to be expanded on, and what needs to be linked to.Eugene Kwan (talk) 04:41, 5 July 2009 (UTC)
thread_title:  lead 

message: Dear Mr (Dr yet?) Kwan, in the above mentioned section I can look as long as I want to, but I can't see a difference between the 2 aldehydes in the matched and the mismatched cases. Both seem to have the methyle group in (S)-configuration, yet the mismatched case shows a transition state with (R)-config. As I believe that the TS shows it correctly, you maybe want to correct the drawing in the reaction equation.
If I'm wrong, please point it out to me where i got on the wrong track.
Thank you.
Schmid  —Preceding unsigned comment added by 85.216.71.39 (talk) 20:54, 27 October 2009 (UTC)
thread_title:  Stereoselectivity: Merged model for stereoinduction 

message: An in-depth coverage of the subject would inevitably stir-up a good part of Organic Chemistry and all its underlying concepts : multistep equilibrations,kinetics,chemo-,regio- and stereoselectivity,notation,mechanisms,catalysis, synthetic methodology,variants of the reaction and more.So it would have to be long and technical.But,
1. Does it really need to go to such lengths and 2.if the answer is yes, should it not make some effort to offer something to the chemically innocent visitor ALSO?
On account 1.I don't see any reason why WP should not try to expand readership among Chemistry students preparing for exams or even qualified chemists but in a different field etc.Even supplying material in the style of an academic review article may not be a bad idea.Making such an approach an appraised prototype though ,may be taken to imply that this is how things should be done ,which I don't agree with because of 2.It seems to me that the layered approach of editing would be in everybody's interest.First the overall picture,set the frame of what is to follow,define the basics, example ,importance history ,a photo or a drawing (an informative one, I mean)in one word the encyclopaedic material and all this with minimal technicalities and minimal linking.Clear concise captivating should the target at this first layer.Other layers to follow AFTER THIS FIRST one can cater to completeness  verifiability and the rest of the scientific stuff. All of the above ,although self evident, do not seem to apply in this present case.I do not  mean to belittle the  work done by the authors as they have produced an excellent assay on the subject .I understand that I am allowed ,in principle,to make my proposal but this is no trivial matter at such level of quality.I would have preferred the original editors doing it.Cleanthis (talk) 16:51, 17 August 2010 (UTC)
thread_title:  A non-WPexpert opinion  on the Aldol Reaction article 

message: I have removed the following comment from the article text, which seems to be referring to :File:Mergedmodel.gif: "The S stereochemistry of the alpha methyl on the mismatched aldehyde should be R, (out of the plane), simmilar to the correctly drawn transition state".  I can't figure out exactly which structure is being referred to.  Can anyone help out?  -- Ed (Edgar181) 16:44, 13 December 2010 (UTC)
thread_title:  Image comment 

message: This article was promoted in 2006, and doesn't appear to meet current FA standards.  See also should be pruned and items incorporated in the text, there are multiple WP:MSH issues, there are WP:MOSBOLD issues throughout, we find an undefined terms in the first paragraph (dimerization, INN), and there is vague prose throughout (One common solution is to form the enolate of one partner first, and then add the other partner under kinetic control.[16] Kinetic control means that the forward aldol addition reaction must be significantly faster than the reverse retro-aldol reaction).  Please work on these issues, so a featured article review will not be needed.  SandyGeorgia (Talk) 15:37, 15 February 2011 (UTC)
thread_title:  FAR

message: I can see that there was a desire to fill in the blank space to the right of the TOC, but I sorta wonder about what is there now.
1.  I really don't think the blank space to the right of TOCs bothers readers.  They can skip to the article pretty fast.  Not like they need that white space filled in.  It's like your house.  Not every room needs filling.  Can have some margin there
2.  If we do keep it, seems like the caption should be worked on and made more lead worthy.  Like definitely simplify it (too "hard" now). The specific chemicals tell us nothing important (they're just liquids, I have to take you on faith anyhow, could be water for all I know).  Better to explain what each flask does and the tubing and all.  And give a generality (enolate in one side, other is for products, or whatever).
3.  What about putting it up high in normal position?  At least it's a photograph and kinda attracts people.  But I would skinny the caption way down.  All that explaining can be done in article, but maybe just saying "laboratory setup for an Aldol reaction" would be enough.  After all, there is plenty of text in the lead anyhow.
TCO (talk) 01:56, 18 February 2011 (UTC)
replies: text: This change to the scheme? One I removed had different weird settings (low resolution, pixelation from gif compression artifacts) and some bonds appeared to be colored incorrectly. I've been gradually working on updating chem diagrams to current MOS standards in chemistry articles...lots of .gif here could be cleaned up in various ways (not flagged by the FAR questioner above, but one of my personal wiki-chem-gnome crusades:). DMacks (talk) 14:57, 18 February 2011 (UTC)
replies: text: No sweat, but how about moving it down in article?  And discussing the setup a bit more (mass transfer, etc.)  TCO (talk) 16:27, 18 February 2011 (UTC)

text: I think having a typical scheme for the reaction is appropriate in the lead.  Can you be more specific about what you mean by "discussing the setup"? Eugene Kwan (talk) 16:38, 18 February 2011 (UTC)
replies: text: I could go along with something other than a reaction-scheme for lede image. A chemist might appreciate the specific details of it (what makes it Aldol and what makes Aldol interesting), chemists and students would be able to interpret it at all (what all the lines mean in the structures), but I think a photo of an experimental setup (especially one that includes the some of the special equipment often needed) also helps draw in other lay readers rather than scaring them off right away. An alternative might be a diagram of an important product molecule that can be made by the reaction (ideally a complex molecule where multiple aldol reactions are used to build it efficiently)--"hey, this reaction might be interesting because it makes a complicated thing I may have heard of so easily!". All the structural details are critical to (and support the chemical importance of) the reaction, but there are at least some aspects that are accessible and maybe interesting to people who don't know much about any of that. I agree with others who have (essentially) said that we shouldn't hide the advanced details, but also that if possible we should include something for lower level readers--being a general-use encyclopedia, not a graduate-level text. DMacks (talk) 16:42, 18 February 2011 (UTC)

text: Separately from the "what image in lede", I like the idea of dDiscussing the setup in more detail...somewhere. In the enolate-control sections, the ideas of amount (by extension, order-of-addition), temperature, and reactivity of reagents are discussed, so an intro paragraph describing the experimental setup (dry-ice bath, cannula transfer, etc.) would fit well. DMacks (talk) 16:42, 18 February 2011 (UTC)
thread_title:  image in lead section 

message: This is truly an outstanding modern synthetic chemistry article, and as one that spends a great deal of time editing chem articles here, it's a pleasure to see one executed and maintained so well (and with such collegiality).  Unusually, I have nothing specific to offer or suggest, vis-a-vis changes, but will keep looking in at History to see its evolution going forward. Besides new reviews and research work coming out—realize, here, the expectation is for secondary, and not primary sources to predominate—I would look to the Chem 206 and other Boger/Evans-type lecture notes online, to see content directions being used in good programs that are less research-oriented and more pedagogic/encyclopedic. (And every once in a while the online graduate research presentations now very common at good programs—Harvard, Illinois, Caltech, etc—will also shed some light on the perspectives of important leaders in the field; if a Denmark student at UIUC prepares a presentation for a graduate course on the current status of Lewis base-mediated ...  well, you get what I mean.) 
Otherwise, I will (with your forbearance) begin to bring other chemistry needs to your attention here, to perhaps inspire some further excellent work. I prepare content, but often cannot take time to create (or solicit from best source) the needed images to make an article complete. As we all know—and Roald Hoffmann nicely reminded us (http://onlinelibrary.wiley.com/doi/10.1002/anie.199100013/abstract, http://www.roaldhoffmann.com/other)—the images are central, and nearly all, sometimes. For instance, I am finishing a rewrite of the stub on David Evans, and there are few extant images I would feel good about being put up in his article.  E.g., vancomycin aglycone would be a nice image to feature, but all the ones in WikiMedia are atrocious.  Would never do that to him.  Cheers, and look for another mssg soon.  LeProf (see LeProf_7272).  — Preceding unsigned comment added by 50.179.92.36 (talk) 21:15, 5 December 2013 (UTC)
thread_title:  Brava, bravo, ladies and gentlemen, brava, bravo 

message: Per earlier discussion regarding a simplified opening, here is a quick draft with a de.wikiedia figure.  Use of this could be done by giving the existing opening a new "General introduction" section heading (to limit effort required).  The figure could also be rejiggered to save space. Comments, action welcome.  Cheers.  LeProf
"
The aldol reaction is a chemical reaction that is important both in nature, where it is central to all of biochemistry taking place in living organisms (e.g., in aldolase enzymes), and in human endeavors in organic chemistry, where it has found great utility to make molecules in the pharmaceutical industry and to allow first academic synthesis of molecules from nature (natural products). Discovered concurrently in the 19th century by Alsatian and Russian chemists, the reaction forms new bonds between carbon atoms (carbon–carbon bonds), by combining at its simplest, a two carbon fragment and a one carbon fragment to create a new three carbon product; in practice, each piece is much larger, because the reaction accommodates further substituents being attached to each fragment. The reaction is distinct in its using a carbon-carbon double bond, drawn C=C, for the two carbon fragment, where one carbon bears a partial negative charge; this is the nucleophile. It is generated as an isomeric form of a ketone such as the common solvent acetone, or the fragrance precursor acetophenone. The isomer is called an enol; under basic conditions it is negatively charged, and so an enolate. For the one carbon fragment (though essentially always bigger than one carbon), the reaction can use the carbon-oxygen double bond, drawn C=O, of an aldehyde such as formaldehyde, acetaldehyde (a relative of acetic acid in vinegar, found in ripe fruits), or benzaldehyde (from bitter almond oil). Notably, as explained further below, a second ketone could also be used to provide the second fragment. The C=O unit of these bears a partial positive charge on its carbon atom; i.e, it is an electrophile. Under carefully controlled conditions, reaction of this pair of nucleophile and electrophile results in a new bond between the atoms bearing the opposite charges, a new carbon-carbon bond.  A base-mediated aldol reaction is illustrated below in "line-angle" form, where intersections of multiple lines imply a further carbon atom.  
The ketone, acetone, shown in black at left, is isomerized in the complete absence of water at very low temperature, and is given its negative charge to provide the needed enolate (by deprotonation with the base LDA, see figure legend and below). In this case, it is a lithium enolate, because of the lithium (Li+) counterion from the LDA. While the negative charge is shown on the oxygen, it actually resides significantly on the terminal (end) carbon of the C=C shown. This negative charge (electron density) "attacks" the partial positive charge of the C=O of acetaldehyde shown in blue. The reaction combines the two fragments, giving the newly formed bond in red. This is termed a condensation reaction for its "condensing" two smaller ones into one larger one. The intermediate formed is called an alkoxide, which is an anionic form of an alcohol, here a lithium alkoxide, given the Li+ counterion present.  When the reaction is quenched with water (H2O, as shown), or when an enzyme shuttles in what's needed, the alkoxide is converted to the final product (with LiOH as byproduct).  The product, an alcohol (akin to the isopropanol of rubbing alcohol), is also termed an aldol, an anachonism combining the words aldehyde and alcohol. The reaction can be performed in a variety of ways that combine of C=C and C=O units (including where a single ketone serves both roles, a reaction called a self-condensation). The resulting aldol has both carbonyl and hydroxyl functional groups (see figure legend), and is extraordinarily common; one example is fructose 1,6-bisphosphate, an intermediate in central metabolism (gluconeogenesis and glycolysis) that is three steps from glucose, and another is the cholesterol-lowering statin drug atorvastatin calcium (Lipitor®). Finally, it is critically noteworthy that the reaction results in the formation of up to two new chiral/stereogenic centers—as in both of these examples—and creating such centers selectively, with only the desired "handedness" present, is both necessary for modern chemistry applications in industry, and tremendously challenging in its practice. It is estimated that the aldol reaction was reported upon XX times in the scientific literature since its discovery, and it is used every second of every day by living systems, and many times daily in laboratory chemistry operations around the world.
"
— Preceding unsigned comment added by 50.179.92.36 (talk) 09:17, 7 December 2013 (UTC)
replies: text: Sorry to be so long in getting back to you.  I failed to mark this talk page to watch, and assumed, not seeing a ping at my Talk page, that you dismissed me as a crazy, and did not reply.  In any case, now seeing your careful review of the proposed lede, I will attend further to it.  See also the note, left today, vis-a-vis the Natural Products page.  Cheers, Le Prof  Leprof 7272 (talk) 20:00, 3 June 2014 (UTC)
thread_title:  Draft related to possible more widely understandable article opening ...