The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Starting from chiral mercapto alcohols 5 in several reaction steps nitrones 7 were formed which underwent spontaneously intramolecular cycloaddition to give diastereomerically pure products 8. However, during the reaction course partial racemization had occurred. In contrast, nitrones 9 in which the chiral center is adjacent to the nitrogen atom afforded a mixture of the two diastereomeric cycloadducts...
The 4-cyano-substituted bicyclic compounds 10 and 11 were prepared by reaction of the aldehyde dimer 7 with a cis-trans mixture of 4-bromo crotononitrile followed by treatment with corresponding N-substituted hydroxylamines. The diastereomers 10a and 10b could be separated by flash chromatography. The key step in the synthesis of compounds 15 and 16 was the Wittig reaction of 13 with cyanomethylene...