2-Alkylidene-4-oxothiazolidine S-oxides - synthesis and stereochemistry
- A series of 5-unsubstituted and 5-substituted 2-alkylidene-4-oxothiazolidine-S-oxides were synthesized by the sulfur-oxidation with m-CPBA. The stereochemistry of 5-substituted sulfoxides was determined by means of NMR spectroscopy and DFT theoretical calculations. It was found that the thermodynamically less stable anti-isomer was initially formed in the course of the oxidation, but it underwent epimerization to the mixture enriched in the more stable syn-isomer, during the work-up process. The higher stability of syn-isomers is ascribed to the stronger hyperconjugative sigma(C-H)->sigma*(S-O) interaction versus the weaker sigma(C-C)->sigma*(S-O) delocalization in their anti-counterparts and to the existence of intramolecular 1,5-CH center dot center dot center dot C hydrogen bonds.
Author details: | Zdravko Dzambaski, Rade Markovic, Erich KleinpeterORCiDGND, Marija Baranac-StojanovicORCiD |
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DOI: | https://doi.org/10.1016/j.tet.2013.05.087 |
ISSN: | 0040-4020 |
Title of parent work (English): | Tetrahedron |
Publisher: | Elsevier |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Year of first publication: | 2013 |
Publication year: | 2013 |
Release date: | 2017/03/26 |
Tag: | 2-Alkylidene-4-oxothiazolidine; CH center dot center dot center dot O hydrogen bonds; Density functional calculations; Diastereoselectivity; Sulfoxide |
Volume: | 69 |
Issue: | 31 |
Number of pages: | 12 |
First page: | 6436 |
Last Page: | 6447 |
Funding institution: | Ministry of Education, Science and Technological Development of the Republic of Serbia [172020]; Deutscher Akademischer Austauschdienst (DAAD) [504 252 70] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |