3‐Aza‐ und syn ‐3,7‐Diazaoctabisvalen Synthesen, Röntgenstrukturanalysen, neue Heterocyclen

3‐Aza‐ and syn ‐3,7‐Diazaoctabisvalene. ‐ Syntheses, X‐ray Structural Analyses, Novel Heterocycles Preparatively useful routes for 3‐aza‐ and syn ‐3,7‐diazaoctabisvalenes have been designed based on well available materials. Thus, 7‐cyano‐3‐azaoctabisvalene ( 4 ) becomes available in a six‐ (five‐) step synthesis from the valence tautomers 7‐cyanotropilidene ⇄ 7‐cyanonorcaradiene ( 7 ⇄ 8 ) (derived dioxides 9 / 10 ) in an overall yield of ca. 30%, syn ‐3,7‐diazaoctabisvalene ( 5 ) in a three‐step synthesis from muco ‐diazidotetrol 30a in ca. 25% overall yield. For 4 and 5 spectroscopic (e.g. 15 N‐NMR resonances, 13 C, 13 C coupling constants) and structural details (X‐ray analyses) are determined. 4 and 5 serve as starting materials for the construction of several novel heteropolycyclic skeletons (e.g. 46 , 48 , 50 , 51 , 52 , 54 ).