Talk:Total synthesis

message: The statement "In some cases the structures of the molecules assigned by spectroscopic methods have been shown to be wrong, when synthesised." is unclear. Does this mean that the synthetic compound provided the correct spectrograph that could not be obtained from the original (because of impurities, irregular crystal habits, etc.)? Or does this mean that the synthetic compound is a new isomer that can only be distinguished from the original by a spectrograph? Collin237  —Preceding unsigned comment added by 166.217.232.85 (talk) 11:44, 29 March 2011 (UTC)
replies: text: The statement is reasonably clear for a reader with appropriate background, though the article as a whole is not detailed enough, e.g., in the richness of examples, to reinforce even simple concepts for more general readers. In answer to this question: One isolates a substance from a natural source, and purifies it to "homogeneity" -- so that regardless of any subsequent purification approach taken, the result of the separation method still only gives a single component. This purified single component is subjected to methods of structure determination—historically, derivitization/fragmentation chemistry and then X-ray crystallography when possible, and broad vibrational, mass spectrometric, absorption (UV-Vis), circular dichroic/polarized light rotation, and magnetic resonance methods, but of late, much more frequently, using NMR methods as primary tools (including multidimensional), and then other methods as supporting data, with crystallography applying most frequently to only organometallic and simpler natural products. Based on the best applicable methods, a structure is often reported, and a name given. Ideally, the structure presented after analysis is of a single stereochemical isomer (i.e., the structure determination is stereospecific). Note, when crystallography is applicable and successful, it produces a accepted solution that is generally considered firm and beyond refute; the issue referred to in the quote in the foregoing student query most generally applies to NMR-determined natural product structures. Errors in this assigned structure can arise in many ways, and their discovery, when it occurs, though the details are complex, happen in one of a couple of simple conceptual ways. (Generalizing and simplifying here, colleagues, apologies.) In the manner currently referred to in the article, a synthetic organic chemist prepares the identical natural product structure (e.g., based on a retrosynthetic analysis of the graphical representation presented by the original purifying and structure determining team); this synthesis is often many steps, either sequential ones, of via a convergent design, and are always based on substantiated chemical coupling steps (i.e., established enough so that their generalizability can be inferred) and on comparable spectroscopic analyses (NMR, MS, IR, UV-Vis, etc.). When a reasonable series of chemical steps with accompanying analytical data provide a product with the same graphical representation as presented by the original purifying and structure determining team, and this single pure component gives final spectroscopic data identical to that originally provided—of each type originally available, as various as it might be (running generally, to tens to hundreds of pages of spectra and related data)—then the original proposed structure is said to have achieved a "proof by synthesis" (as much as proof in any scientific area might be achieved). In cases where the data of the reasonably outlined and supported synthetic product do not match the original data for the isolated substance, then the statement made and quoted above obtains, with the conclusion that the original, less-dissected and likely less-scrutinized original structure proposal is incorrect. This all-too-brief and all-too-weakly-illustrated article should make the process and the importance of this regular occurring organic chemistry scenario much clearer.  Note, there is no mention in my explanation of a "spectrograph", which is not a term generally applied to the analytical instrumentation used by synthetic/NP organic chemists. See references appended for further examples and explanation.
*http://www.sciencedirect.com/science/article/pii/S0968089611004391
*http://books.google.com/books?id=HOZsEN1MVCMC&pg=PA77&lpg=PA77&dq=Structure+correction+organic+synthesis&source=bl&ots=OWv51EAkdV&sig=F4cLpRHGt1m4YbV2uWYSKvN-PiU&hl=en&sa=X&ei=N15gU-bcCYWtyATX-oGADg&ved=0CGEQ6AEwBQ#v=onepage&q=Structure%20correction%20organic%20synthesis&f=false
*http://www.brocku.ca/mathematics-science/departments-and-centres/chemistry/faculty/Hudlicky/Synthesis-1998-275.pdf
*http://pubs.acs.org/doi/abs/10.1021/ol0165894
*http://pubs.acs.org/doi/abs/10.1021/jo00073a057
*http://www.sciencedirect.com/science/article/pii/S0040403900737026
*http://www.sciencedirect.com/science/article/pii/S0040403900988907
*http://pubs.acs.org/doi/abs/10.1021/jo00220a001
*http://pubs.acs.org/doi/abs/10.1021/ol102599e
Le Prof 71.239.82.39 (talk) 02:41, 30 April 2014 (UTC)
thread_title: Spectrography

message: The article claims that camphor was the first commercial total synthesis, but the first reference discusses the synthesis of alizarin in 1869 as having spurred the German dye industry.  The alizarin page itself discusses the synthesis and notes that the market for the compound from its traditional source collapsed overnight upon the report of the synthesis.  —Preceding unsigned comment added by 136.152.155.72 (talk) 23:38, 19 April 2011 (UTC)
replies: text: Apt point, and having used alizarin as the basis for developing a teaching lab at UChicago in early 90s, can verify, the historical points made.  Article edit required.  Le Prof Leprof 7272 (talk) 05:55, 5 June 2014 (UTC)
thread_title: History

message: This is not about this article, but about articles within :Category:Total synthesis. See Talk:Morphine#Merge_morphine_total_synthesis for a discussion.  Blue Rasberry (talk) 16:56, 22 January 2014 (UTC)
replies: text: In a word, yes.  See responses from me, this date, at Talk:Morphine#Merge_morphine_total_synthesis, and immediately below.  Le Prof 71.239.82.39 (talk) 03:41, 30 April 2014 (UTC)
thread_title: Should total synthesis articles exist?

message: A significant proportion of all drugs on market have links to natural products chemistry, and total synthesis is central to their development, understandings of their mechanism of action, etc. As well, total synthesis is considered the single greatest motivation and proving ground of new, general synthetic methodology, and provides the most highly regarded of training venues for synthetic organic chemists for academia and industry. This article does not begin to relate the central importance of this subject to all of modern organic chemistry, in the past century or in the beginnings of this one.  Le Prof  71.239.82.39 (talk) 02:49, 30 April 2014 (UTC)
thread_title:  Strikingly important subject, strikingly poor article at present... 

message: ...to this article, I have addressed what serious deficiencies I can, quickly, and tagged the rest to call further attention to the article.  As long as this article is so poor, there will be broad misunderstanding by others here at WP, about the distinctiveness of TS work, and its fundamental importance to org synth and medichem. Please, others, bring what you can to bear on this article. See edit summaries for the specific changes made. Note, I have great respect for KC's group and corpus, but his work should not form the sole basis for this article (obviously), and passing mentions of Corey syntheses, inserted unreferenced, cannot be tolerated as a practice.  Le Prof  Leprof 7272 (talk) 06:01, 5 June 2014 (UTC)
thread_title: Since no one seems to be attending

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thread_title:  External links modified 

message: I made an invisible comment about this. The examples section should be expanded a lot and be made into a list. There are dozens of very good total synthesis examples that can be listed to highlight the bredth and importance of total synthesis, some of which should be able to be linked to wiki pages. Though, it is not necessary to linked them to wiki pages, it could also be used as an opertunity to make red links to pages that should be created.
While I could do this, I admit that I don't particularly want to lol (hence me sharing it as an idea on the talk page). Maybe I will in the future.
As a side note, the history section should probably be overhauled when the example section is expanded.
Tautomers (talk) 23:14, 24 June 2021 (UTC)
thread_title:  Improve Examples Section