Langsame Inversion am pyramidal gebundenen Stickstoff: Isolierung und Epimerisierung diastereomerer N‐Methoxy‐3,3‐di‐methoxycarbonyl‐5‐cyan‐1, 2‐oxazolidine. Vorläufige Mitteilung

Abstract

Abstract Two crystalline diastereomeric N‐methoxy‐3, 3‐di‐methoxycarbonyl‐5‐cyano‐1, 2‐oxazolidines (II and III) have been isolated. The pyramidal arrangement at the respective nitrogen atoms does not invert at room temperature. The A RRHENIUS activation energy for the epimerization of the thermodynamically less stable isomer to the more stable one in bromoform solution is 29,2 ± 0,5 kcal/Mol (log A = 14,2 ± 0,3).