Oxidation of N-aminopyrrolidine 5 with tert-butyl hypochlorite at -130 o C yields the 1,1-disubstituted diazene which is stable in dimethyl ether solution at this temperature. Thermal (-90 o C) or photochemical (-130 o C, λ>330 nm) decomposition of 4 fumishes singlet alkyl propargyl biradical 1, which undergoes fragmentation to 16, cyclization to 17, and disproportionation to 18 and 19 (Table I)