Unusual oxidative rearrangement of 1,5-diazadecalin

Upon treatment with (PhIO)n or PhI(OAc)2, 1,5-diaza-cis-decalin undergoes oxidation at the more hindered position along with fragmentation to yield the ring-expanded bislactam. The cis and trans 1,5-diazadecalins both undergo the same elimination indicating a potential stereoelectronic preference for oxidation at the more substituted carbon alpha to the nitrogen. Oxidation at the less hindered positions of 1,5-diaza-cis-decalin was accomplished on the Boc-protected derivative to provide an intermediate for the synthesis of 2,6-substituted-1,5-diaza-cis-decalins.