Crotonyl azides

Crotonic acid and derivs 3 C562—C563 crotonyl azide 3 C563... 

Crotonyl Azide (Called Crotonsaureazid in Ger), CH3.CH CH.CO.N3 mw 111.10, N37.83% clear liq having a sharp odor bp-begins to decomp at 30° rapidly evolves N at 75° was prepd by treating crotonyl chloride in ether soln with NaNj (Refs 1 2)... 

Perfect retention of the geometrical configurations has been observed in the Curtius rearrangement of cis- and franr-crotonyl azides (10), which respectively give cis- and franr-propenyl isocyanates (11), characterized as their urea derivatives (12 Scheme 8). The cis isomers (10b) and (11b) tend to isomerize thermally to the trans isomers (10a) and (11a) respectively. 

Unsaturated Acids. The formation of olefinic acid azides by the sodium azide procedure appears to be limited only by the availability of the acid chloride. Examples of a,/3-olefinic acid azides prepared by this method are crotonyl, cinnamoyl, and methacrylyl azides. The hydrazide route to the azide is sometimes complicated by ride reactions. The esters of oleic acid and elaidic acid give the respective hydra-zides in good yield under the usual conditions, but severe treatment causes reduction of the unsaturated hydrazides to stearoyl hydrazide. ... 

Conversion of the hydrazides of a,/3-olefinic acids to azides is frequently impossible owing to cyclization upon treatment with nitrous acid. Cin-namoyl hydrazide and nitrous acid, for example, yield l-nitroso-5-phenyl-3-pyrazolidone. Crotonyl hydrazide and m-nitrocinnamoyl... 

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