Cinnamaldehyde aluminum hydrides

Chrysene, 45, 95 Cinnamaldehyde, 45, 36 48, 79 reaction with hydrazine, 47, 99 Cinnamic acids and derivatives, conversion to phenylcyclopropanes with lithium aluminum hydride,... 

Many more examples exist for reduction of the carhonyl only. Over an osmium catalyst [763] or platinum catalyst activated by zinc acetate and ferrous chloride [782] cinnamaldehyde was hydrogenated to cinnamyl alcohol. The same product was obtained by gentle reduction with lithium aluminum hydride at —10° using the inverse technique [609], by reduction with alane (prepared in situ from lithium aluminum hydride and aluminum chloride)... 

Better reagents than lithium aluminum hydride alone are its alkoxy derivatives, especially di- and triethoxyaluminohydrides prepared in situ from lithium aluminum hydride and ethanol in ethereal solutions. The best of all, lithium triethoxyaluminohydride, gave higher yields than its trimethoxy and tris(/er/-butoxy) analogs. When an equimolar quantity of this reagent was added to an ethereal solution of a tertiary amide derived from dimethylamine, diethylamine, W-methylaniline, piperidine, pyrrolidine, aziridine or pyrrole, and the mixture was allowed to react at 0° for 1-1.5 hours aldehydes were isolated in 46-92% yields [95,1107], The reaction proved unsuccessful for the preparation of crotonaldehyde and cinnamaldehyde from the corresponding dimethyl amides [95]. 

Normally the ethereal solution of the substance is added to the solution of the hydride in ether other reducible groups are then attacked in addition to the olefinic bond. If, however, the lithium aluminum hydride is added gradually to the substance (the so-called inverse reduction ), then saturation of the C=C bond can generally be avoided. For instance, cinnamaldehyde affords 3-phenyl-l-propanol by one method and cinnamyl alcohol by the other, both... 

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