Diastereoselektive Addition von Thiocarbonsäuren an 1-(Methacryloyl)prolin- und -prolinol-Derivate (Aminosäuren ; 15) [article]

Franz Effenberger, Heinz Isak, Universität Stuttgart, Universität Stuttgart
Thiocarboxylic acids 6 add to 1-(methacryloyl)-substituted proline and prolinol derivatives stereoselectively to give the 1-[3-(acylthio)-2-methylpropionyl]proline and -prolinol derivatives 7,7' and 9. The less soluble (2S,2'R)-diastereomers are obtained in optical yields 98% by digestion of the crude products, the configuration of which was determined by acid hydrolysis of (2S,2'R)-7,7' to (R)-3-mercapto-2-methylpropionic acid [(R)-8]. The stereoselectivity of the additions may be explained by
more » ... may be explained by a sevenmembered ring intermediate with an intramolecular H bridge, to which the S-nucleophiles add preferentially to give the compounds with the (2'R)-configuration.
doi:10.18419/opus-1115 fatcat:l6a4e37jtfctljrofddzt4oub4