Highly regioselective and stereoselective cascade reductive cyclization of δ-ketoamide: practical access to oxa-bridged benzazepines.

A highly regioselective and stereoselective cascade reduction cyclization of δ-ketoamide is realized under LiAlH4-assisted conditions, providing an atom-economical and straightforward approach to access oxa-bridged benzazepines in moderate to good yields. This method overcomes the limitations of aldehydes or other precursors of primary alcohols and realizes the cascade reduction cyclization of secondary alcohol anions generated in situ from ketones. The reaction proceeds with broad substrate scope and good functional group compatibility.