Preparation of 9-aryl (or heteroaryl)methylidene-10-(methoxyimino)-phenanthrenes and their thermal electrocyclisation to fused quinolines

o-Quinone methanide N-methoxyimines 6a-c, 7a-c, 11a-b and 12a , easily prepared from the reaction of 10-(methoxyimino)phenanthrene-9-one ( 3 ) with phosphonium salts 5a-c, 10a-b in the presence of lithium hydroxide, are thermally converted into dibenzo[f,h]quinolino[2,3-x]fused compounds 9a-c and 13a-b , in high yield.