Formation of Benzo[e]cycloalk[g][1,4]oxazocinones by Reaction of N-Mesyl- or N-Tosyl-N-2-[(1-cycloalken-1-yl)phenyl]glycines with Molecular Bromine

The synthesis of new cycloalkene annelated benzoxazocinones from N-tosyl- or N-mesyl-N-[2-(1-cycloalken-1-yl)phenyl]glycines was reported. Upon stirring of these glycines with bromine at room temperature, regardless of the size of the carbocyclic ring, benzo[e]cycloalk[g][1,4]oxazocinones were formed, in which an olefin moiety is induced between the C1=C11b or C1=C12b carbon atoms. The use of iodine for this purpose in the case of a cyclopentenyl derivative leads to a similar cyclization, while upon reaction of this halogen with a cyclohexenyl homologue forms a spiro-fused 2′-iodo[benzoxazepine-5,1′-cyclohexane].