Highly Regio‐ and Diastereoselective 1,3‐Dipolar Cycloaddition of Nitrile Oxides to 2,4‐Dimethyl‐3H‐1,5‐Benzodiazepines: Synthesis of Bis[1,2,4‐Oxadiazolo][1,5]Benzodiazepine Derivatives

The 1,3‐dipolar cycloaddition reaction of nitrile oxides to 2,4‐dimethyl‐3H‐1,5‐benzodiazepines 1a–1c led, with completely regio‐ and diastereoselectivity, to new 3a,4a,8,13‐tetrahydro‐4H‐bis[1,2,4‐oxadiazolo][4,5‐a:5′,4′‐d][1,5]benzodiazepines 3a–3g. The structures of the synthesized bis‐adducts 3a–3g were elucidated by spectral methods and X‐ray crystallographic analysis.