Z. Naturforsch. 2012,
67b, 1045 – 1055
doi:10.5560/ZNB.2012-0146
2,5-Dihydro-1,3-thiazoles as Scaffolds in the Synthesis of O,N-Diacyl O,N-Acetals in a One-pot Reaction
Timo
Stalling,
Fabian
Brockmeyer,
Denis
Kröger,
Almuth
Schwäblein, and
Jürgen
Martens
Institut für Reine und Angewandte Chemie, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
Received May 29, 2012 / published online October 8, 2012
Dedicated to Professor Heribert Offermanns on the occasion of his 75th birthday
The Asinger reaction is a very powerful tool to form 2,5-dihydro-1,3-thiazoles in high yields. Treating these heterocyclic imines with acid chlorides followed by adding sodium carboxylates led to a large number of new O,N-diacyl O,N-acetals. Using chiral starting materials, a high diastereoselectivity was observed in several cases. X-Ray structures document the constitution and clarify the relative configuration of the prepared O,N-diacyl O,N-acetals.
Key words: Imines, Acetals, N-Acyliminium Ion, Carboxylates, Stereochemistry