The syntheses of 4b,5a-dihydro-5H-benzo[3,4]-phenanthro[1,2-b]azirine and 1a,11b-dihydro-6,11-dimethyl-1H-benz[3,4]anthra[1,2-b]azirine

The syntheses of the K-imine derivatives of carcinogenic benzoc]phenanthrene and 7,12-dimethylbenz-a]anthracene are described. Treatment of trans-5-azido-5,6-dihydrobenzoc]phenanthren-6-ol ( 3 ) and trans-6-azido-5,6-dihydrobenzoc]phenanthren-5-ol ( 5 ) with thionyl chloride yielded the corresponding β-chloro azides, which in turn, were reacted with lithium aluminium hydride to give 4b,5a-dihydro-5H-benzo3,4]-phenanthro1,2-b]azirine ( 2 ). In a similar manner trans-5-azido-5,6-dihydro-7,12-dimethylbenza]anthracen-6-ol ( 11 ) and trans-6-azido-5,6-dihydro-7,12-dimethylbenza]anthracen-5-ol ( 13 ) were transformed to the respective chloro azides and, converted into 1a,11b-dihydro-6,11-dimethyl-1H-benz3,4]anthra1,2-b]azirine ( 10 ).