The photolysis of berbine N-oxides

Article abstract of DOI:10.1016/S0040-4020(01)83116-1

Photolysis of trans-canadine N-oxide (3) leads to lactam 5 and formamide 7. Similarly, photolysis of trans-xylopinine N-oxide (12) supplies lactam 14 and amide 15. Oxaziridine 4 is a probable intermediate in these transformations, so that selective oxidation of the berbine nucleus at C-6 has been achieved, accompanied by fission of the N-7-C-14 bond. LAH reduction of lactam 5 gives rise to dibenzazecine 8, while similar treatment of amide 7 generates dibenzazonine 10. Alternatively, acid hydrolysis of 7 furnishes dibenzazonine 11.