Document Detail


An aerobic oxidation/homolytic substitution-cascade for stereoselective methylsulfanyl-cyclization of 4-pentenols.
MedLine Citation:
PMID:  23450339     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
4-Pentenols (dihomoallylic alcohols) are oxidized by cobalt(ii)-activated dioxygen in solutions of dimethyl disulfide and cyclohexa-1,4-diene to afford methylsulfanyl (CH3S)-functionalized tetrahydrofurans in up to 74% yield. The reaction is a cascade, composed of oxidative alkenol cyclization providing tetrahydrofuryl-2-methyl radicals, which are trapped in dimethyl disulfide. Homolytic methylsulfanyl substitution by carbon radicals is a slow reaction, as exemplified by the rate constant of kSCH3 = 3 × 104 M-1 s-1 (70 °C) derived from competition kinetics for the reaction between dimethyl disulfide and the trans-2-phenyltetrahydrofuryl-5-methyl radical. Methylsulfanyl-cyclizations therefore are experimentally performed in neat dimethyl disulfide, containing the minimum amount of cyclohexa-1,4-diene necessary for attaining almost quantitative alkenol conversion. The oxidative tetrahydrofuran synthesis occurs with noteworthy (>99%) 2,5-trans-stereoselectivity, as shown by the synthesis of diastereomerically pure 2,3- and 2,3,3-substituted 5-(methylsulfanyl)methyltetrahydrofurans from stereodefined 1,2-di- and 1,2,2-trisubstituted 4-pentenols. Changing the chemical nature of the disulfide reagent or the alkenol extends the scope of alkylsulfanyl-cyclization to ethylsulfanyl-cyclization, allylsulfanyl-transfer, or tetrahydropyran synthesis.
Authors:
Patrick Fries; Melanie Kim Müller; Jens Hartung
Related Documents :
24588659 - Screening methods to identify indole derivatives that protect against reactive oxygen s...
23414339 - Cu(i)-catalyzed domino reaction of 3-cyclopropylideneprop-2-en-1-ones.
24820329 - Oxidatively generated base damage to cellular dna by hydroxyl radical and one-electron ...
25054839 - Asymmetric synthesis of spiro[isoxazolin-3,3'-oxindoles] via the catalytic 1,3-dipolar ...
23062829 - Kinetics of acetaminophen degradation by fenton oxidation in a fluidized-bed reactor.
24939819 - Asymmetric ozone oxidation of silylalkene using a c2 -symmetrical dialkoxysilyl group a...
18207709 - In vitro phototoxicity of dihydropyridine derivatives: a photochemical and photobiologi...
20685279 - A concise synthesis of beta-sitosterol and other phytosterols.
2582539 - Biotransformation of terodiline. v. stereoselectivity in hydroxylation by human liver m...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-3-1
Journal Detail:
Title:  Organic & biomolecular chemistry     Volume:  -     ISSN:  1477-0539     ISO Abbreviation:  Org. Biomol. Chem.     Publication Date:  2013 Mar 
Date Detail:
Created Date:  2013-3-1     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101154995     Medline TA:  Org Biomol Chem     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Fachbereich Chemie, Organische Chemie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany. hartung@chemie.uni-kl.de.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Relationships Among Veteran Status, Gender, and Key Health Indicators in a National Young Adult Samp...
Next Document:  Measured Gain in Projection With the Extended Columellar Strut-Tip Graft in Endonasal Rhinoplasty.