|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
Synthesis and structural characterization of cis- and trans-fused 4a,5,6,7,8,8a-hexahydro-2H,4H-1,3-benzodithiines and their 2-methyl and 2,2-dimethyl derivativesстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Pihlaja K., Klika K.D., Sinkkonen J., Ovcharenko V.V., Maloshitskaya O.A., Sillanpää R., Czombos J.
- Журнал: Journal of Organic Chemistry
- Том: 67
- Номер: 6
- Год издания: 2002
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 1910
- Последняя страница: 1917
- DOI: 10.1021/jo011021u
- Аннотация: Both cis- and trans-fused 4a,5,6,7,8,8a-hexahydro-2H,4H-1,3-benzodithiine together with their 2-methyl and 2,2-dimethyl derivatives were prepared as racemates from the appropriate dithiols obtained via multistep syntheses. The products were characterized by 1H and 13C NMR, mass spectrometry, and for two of the cis-fused compounds by X-ray diffraction. 1H, 1H vicinal coupling constants indicated that all compounds attain chair - chair conformations as their predominant conformations. All three trans-fused isomers exist in totally biased chair - chair conformations and are essentially conformationally locked, whereas the cis-fused compounds are conformationally mobile and can potentially attain either the S-in or the S-out conformation. The interconversion of the conformers is fast on the NMR time-scale at ambient temperatures, but at 213 K 4ar,5,6,7,8,8ac-hexahydro-1,3-benzodithiine freezes out into a 83:17 mixture of the S-in and S-out forms, respectively. Both 2c-methyl-4ar,5,6,7,8,8ac-hexahydro-1,3-dithiine and the dimethyl derivative adopt almost exclusively the S-in conformer at ambient temperature whereas 2t-methyl-4ar,5,6,7,8,8ac-hexahydro-1,3-dithiine is a 5:1 mixture of the S-out and S-in conformers.
- Добавил в систему: Малошицкая Ольга Александровна