Abstract:
The 1-(2-aminoethyl)aziridine (aziridine dimer) 1 reacts with acetylene dicarboxylates to give 1,4-diaza- 5-oxobicyclo[4.3.0]nonanes (7-azaindolizines) 3 together with the usual enamine adducts 4; the product structures are confirmed spectroscopically and, in the 3 also by X-ray diffraction and by an independent synthesis from furan 5.