Synthesis of bridgehead nitrogen heterocycles

Reductive cyclizations of N‐[2‐(2‐pyridyl)ethyl]imides were accomplished by employing a palladium on carbon catalyst in ethanolic acetic acid as the hydrogenation medium. Reduction of the corresponding N‐[2‐(2‐quinolyl)ethyl]imides ceased at the 1,2,3,4‐tetrahydroquinolyl stage. Controlled reduction of the tetrahydroquinolyl imides with sodium borohydride gave amido alcohols which afforded bridgehead nitrogen heterocycles upon cyclodehydration.