A new and efficient access to oxazoline-5-carboxylates and amino acid derivatives with cyclopropyl groups

Preparation of 4-spirocyclopropane-annelated oxazoline-5-carboxylates is demonstrated by treating methyl 2-chloro-2-cyclopropylideneacetates with carboxamides under basic conditions. The reaction involves a domino transformation in a Michael addition fashion followed by an intramolecular nucleophilic substitution.