We wished to prepare the a-methylene-y-bromoglutaric acid 11. Attempts to accomplish this from the known1 y-methyleneglutamic acid by diazotization in the presence of sodium bromide2 were frustrated by persistent lactone formation. As an alternative, the selective debromination of the tribromide I was explored. The latter is readily prepared by Hell- Volhard-Zelinsky bromination of a-methyleneglutaryl chloride.
