Iodolactonization Reaction Research Articles

Aminosäureester als chirale Hilfsgruppen in Lewis‐Säure‐katalysierten Diels‐Alder‐Reaktionen

Amino Acid Esters as Chiral Auxiliaries in Lewis Acid Catalyzed Diels‐Alder ReactionsCyclopentadiene, cyclohexadiene and alkyl‐substituted butadienes react with N‐acryloyl‐, N‐crotonoyl‐ and N‐(4‐nitro‐cinnamoyl)‐(S)‐proline benzyl and allyl ester in the presence of Lewis acids to give the cycloadducts in high yields and with stereoselectivities of up to 97:3 for the endo isomers. The sense of the asymmetric induction in these reactions can be directed by the use of differently coordinating catalysts (e.g. TiCl4: (2R):(2S) = 96:4; EtAlCl2: (2R):(2S) = 10:90 at 0°C). In the TiCl4‐catalyzed reactions with the fumaric acid derivatives the ratio of the diastereomers reaches values of up to 112:1 in the presence of 0.5–1 equivalent of the Lewis acid, thus indicating an efficient cooperation between the chiral auxiliaries. Higher catalyst/substrate ratios induce a reversal in the sense of the asymmetric induction. From the cycloadducts the chiral auxiliaries are removed by hydrogenolysis and subsequent hydrolysis of the proline amides. Alternatively, the cleavage of the amide bonds can be carried out by O‐alkylation with oxonium salts and subsequent hydrolysis of the iminium salts formed or by the application of an iodolactonization reaction.

Structural effect on the iodolactonization of unsaturated organophosphorus compounds

The compound 1a , γ,δ-unsaturated phosphate was not able to perform the iodolactonization reaction. But a minor change of its structure makes the iodine induced cyclization reaction succeed.

ChemInform Abstract: 1,6‐DIHYDRO‐3(2H)‐PYRIDINONES. IX. A REGIOSELECTIVE SYNTHESIS OF ETHYL 3‐METHOXYCARBONYLMETHYL‐4‐OXOPIPERIDINE‐1‐CARBOXYLATE FROM ETHYL 3‐HYDROXY‐1,2,3,6‐TETRAHYDROPYRIDINE‐1‐CARBOXYLATE

AbstractAuf den im Formelschema angegebenen Wegen werden die für Alkaloidsynthesen benötigten Ausgangsprodukte (V) und (VIII) hergestellt.

1,6-Dihydro-3(2H)-pyridinones. IX. A regioselective synthesis of ethyl 3-methoxycarbonylmethyl-4-oxopiperidine-1-carboxylate from ethyl 3-hydroxy-1,2,3,6-tetrahydropyridine-1-carboxylate.

The title compound (6) was prepared from ethyl 3-hydroxy-1, 2, 3, 6-tetrahydropyridine-1-carboxylate (2) via a regioselective hydroxylation at the C-4 position of the olefin (7) by utilizing an iodolactonization reaction.

β-Lactones as kinetic products in the iodolactonization reaction

Download options Please wait... Article information DOI https://doi.org/10.1039/C3972000472A Article type Paper Download Citation J. Chem. Soc., Chem. Commun., 1972, 472a-472a BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions β-Lactones as kinetic products in the iodolactonization reaction W. E. Barnett and W. H. Sohn, J. Chem. Soc., Chem. Commun., 1972, 472a DOI: 10.1039/C3972000472A To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author William E. Barnett Won H. Sohn

Formation of β-lactones in the iodolactonization reaction

Formation of β-lactones in the iodolactonization reaction

Assignment of the Olefinic Position in Unsaturated Acids by Means of the Iodolactonization Reaction

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAssignment of the Olefinic Position in Unsaturated Acids by Means of the Iodolactonization ReactionEugene E. van Tamelen and Maurice ShammaCite this: J. Am. Chem. Soc. 1954, 76, 9, 2315–2317Publication Date (Print):May 1, 1954Publication History Published online1 May 2002Published inissue 1 May 1954https://doi.org/10.1021/ja01638a010RIGHTS & PERMISSIONSArticle Views638Altmetric-Citations92LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (339 KB) Get e-Alerts Get e-Alerts