2,2,9-trimethyl-1,6-dioxa-3,4,9-triazaspiro[4.4]non-3-ene

5,5-dimethyl-2,2-diphenoxy-Δ3-1,3,4-oxadiazoline

2-ethoxy-2,5,5-trimethyl-1,3,4-oxadiazole

hydrazine monoborane

hydrazine-N,N'-dicarboxylic acid bis-isopropylidenehydrazide