Andrea Virányi

1,7-Electrocyclisations of stabilised azomethine ylides

Ester-stabilized a,b:g,d-unsatd. azomethine ylides were generated by the deprotonation method from isoquinolinium salts. 1,7-Electrocyclization of these dipoles followed by a 1,5-hydrogen shift, gives tetrahydro[5,6]azepino[2,1-a]isoquinolines I (R = MeO2C, PhCH2, PhCO, CH2:CHCH2).

Synthesis of indazole-N-oxides via the 1,7-electrocyclisation of azomethine ylides

The first examples of the 1,7-electrocyclization of azomethine ylides onto a nitro group, to give benz-1,2,6-oxadiazepine intermediates are reported. Subsequent ring contraction results in the formation of indazole-N-oxides.

Synthesis of indazole-N-oxides via the 1,7-electrocyclization of azomethine ylides

The first examples of the 1,7-electrocyclization of azomethine ylides onto a nitro group, to give benz-1,2,6-oxadiazepine intermediates are reported. Subsequent ring contraction results in the formation of indazole-N-oxides.

Synthesis of pyrrolo[3,4-c]quinolines by 1,5-electrocyclisation of non-stabilised azomethine ylides

A new route to the pyrrolo[3,4-c]quinoline ring system was developed via the 1,5-dipolar electrocyclization reactions of azomethine ylides derived from easily available 3-formylquinoline derivs. The intermediacy of azomethine ylides was shown by the trapping of the proposed dipoles with N-phenylmaleimide.

A convenient synthesis of pyrrolo[3,4-c]quinolines

Synthesis of Pyrrolo[3,4-c]quinolines Andrea Virányi,a Miklós Nyerges,*a Gábor Blaskó,b László Tőkea a Research Group of the Hungarian Academy of Sciences, Department of Organic Chemical Technology, Technical University of Budapest, 1521 Budapest P.O.B. 91, Hungary b EGIS Pharmaceuticals Ltd., 1475 Budapest P.O.B. 100, Hungary Fax +36(1)4633648; E-mail: mnyerges@mail.bme.hu Received 13 June 2003; revised 2 September 2003