Dithians

Structures of 1,2-dithiane, 1,3-dithiane, and 1,4-dithiane

Dithianes are heterocyclic compounds that consist of a cyclohexane structure in which two methylene groups are replaced by sulfur atoms. There are three isomeric forms, 1,2-dithiane, 1,3-dithiane and 1,4-dithiane.

1,2-dithianes

Due to the possible dihedral angles of the sulfur-sulfur bond, 1,2-dithianes form different enantiomers .

1,3-dithianes

Due to their inert behavior towards various synthesis conditions, 1,3-dithianes are a good protective group for carbonyl groups . They are formed when the carbonyl compound reacts with 1,3-propanethiol with the formation of water. The protecting group can with mercury compounds such as mercury (II) chloride of mercury (II) oxide are removed. Because of the very unpleasant odor of 1,3-propanethiol, alternative reagents for the formation of 1,3-dithianes have also been developed. 1,3-Dithianes were used in the total synthesis of natural products .

1,3-Dithianes are used, for example, in the Corey-Seebach reaction as a protective group for the umpolung of carbonyl compounds with organolithium compounds such as butyllithium .

1,4-dithianes

1,4-dithianes can be obtained by reducing 1,2-ethanedithiol with metallic sodium and then reacting with 1,2-dibromoethane under suitable conditions . However, the main products are polymeric structures. The thermal decomposition of these polymers also leads to the formation of 1,4-dithiane.

Web links

Portal for Organic Chemistry: Contribution to the Corey-Seebach reaction

Individual evidence

^ Göran Claeson, Gaylord M. Androes, Melvin Calvin: The Energy Barrier between the Enantiomers of 1,2-Dithiane. In: Journal of the American Chemical Society. 82, 1960, pp. 4428-4429, doi : 10.1021 / ja01501a077 .
↑ Qun Liu, Guangbo Che, Haifeng Yu, Yingchun Liu, Jingping Zhang, Qian Zhang, Dewen Dong: The First Nonthiolic, Odorless 1,3-Propanedithiol Equivalent and Its Application in Thioacetalization. In: The Journal of Organic Chemistry. 68, 2003, pp. 9148-9150, doi : 10.1021 / jo034702t .
↑ Miguel Yus, Carmen Najera, Francisco Foubelo: The role of 1,3-dithianes in natural product synthesis. In: Tetrahedron. 59, 2003, pp. 6147-6212, doi : 10.1016 / S0040-4020 (03) 00955-4 .
↑ Bengt-Thomas Gröbel, Dieter Seebach: Umpolung of the reactivity of carbonyl compounds through sulfur-containing reagents. In: Synthesis , 1977.6 (1977): pp. 357-402.
↑ N. Beverley Tucker, E. Emmet Reid: Cyclic and Polymeric Compounds from the Reactions of Ethylene Mercaptan with Polymethylene Halides. In: Journal of the American Chemical Society. 55, 1933, pp. 775-781, doi : 10.1021 / ja01329a052 .

[1] Göran Claeson, Gaylord M. Androes, Melvin Calvin: The Energy Barrier between the Enantiomers of 1,2-Dithiane. In: Journal of the American Chemical Society. 82, 1960, pp. 4428-4429, doi : 10.1021 / ja01501a077 .

[2] Qun Liu, Guangbo Che, Haifeng Yu, Yingchun Liu, Jingping Zhang, Qian Zhang, Dewen Dong: The First Nonthiolic, Odorless 1,3-Propanedithiol Equivalent and Its Application in Thioacetalization. In: The Journal of Organic Chemistry. 68, 2003, pp. 9148-9150, doi : 10.1021 / jo034702t .

[3] Miguel Yus, Carmen Najera, Francisco Foubelo: The role of 1,3-dithianes in natural product synthesis. In: Tetrahedron. 59, 2003, pp. 6147-6212, doi : 10.1016 / S0040-4020 (03) 00955-4 .

[4] Bengt-Thomas Gröbel, Dieter Seebach: Umpolung of the reactivity of carbonyl compounds through sulfur-containing reagents. In: Synthesis , 1977.6 (1977): pp. 357-402.

[5] N. Beverley Tucker, E. Emmet Reid: Cyclic and Polymeric Compounds from the Reactions of Ethylene Mercaptan with Polymethylene Halides. In: Journal of the American Chemical Society. 55, 1933, pp. 775-781, doi : 10.1021 / ja01329a052 .