Preparation of 9-amino-1,9-diazatricyclo[6.4.0.04,8]dodecane-2,10-dione by a retro-Diels-Alder reaction

Abstract

Treatment of di-endo- or di-exo-3-aminobicyclo[2.2.1]hept-5-ene-2-carbohydrazides (1a and 1b) with ethyl 2-(2-oxocyclopentyl)acetate (2) yields norbornene-condensed 9-amino-1,9-diazatricyclo[6.4.0.04,8]dodecane-2,10-diones 3a and 3b, the condensed bis(lactams) 4a and 4b and (from 1b and 2) the cyclopenta[c]pyridazinone 5. After separation, 3a and 3b both decompose on heating by loss of cyclopentadiene to give 9-amino-1,9-diazatricyclo[6.4.0.04,8]dodecane-2,10-dione (6). © Wiley-VCH Verlag GmbH, 2001.