Triethoxyaluminum hydride, lithium

Lithium triethoxyaluminum hydride, 68 Lithium trimethoxyaluminum hydride, 62... 

Lithium triethoxyaluminum hydride Aluminate (1-), triethoxyhydro-, lithium (8) Aluminate (1-), triethoxyhydro-, lithium, (1-4), (9) (17250-30-5)... 

Lithium triethoxyaluminum hydride Aluminate (1-), triethoxyhydro-, lithium,... 

Pseudoephedrine amides can be converted directly into highly enantiomerically enriched aldehydes using Brown and Tsuka-moto s lithium triethoxyaluminum hydride reagent (eq... 

Lithium triethoxyaluminum hydride is a more powerful reagent which reduces tert-amides and nitriles to the corresponding aldehydes. ... 

Reducing agents Aluminum hydride. Bis-3-methyl-2-butylborane. n-Butyllithium-Pyridine. Calcium borohydride. Chloroiridic acid. Chromous acetate. Chromous chloride. Chromous sulfate. Copper chromite. Diborane. Diborane-Boron trifluoride. Diborane-Sodium borohydride. Diethyl phosphonate. Diimide. Diisobutylaluminum hydride. Dimethyl sulfide. Hexamethylphosphorous triamide. Iridium tetrachloride. Lead. Lithium alkyla-mines. Lithium aluminum hydride. Lithium aluminum hydride-Aluminum chloride. Lithium-Ammonia. Lithium diisobutylmethylaluminum hydride. Lithium-Diphenyl. Lithium ethylenediamine. Lithium-Hexamethylphosphoric triamide. Lithium hydride. Lithium triethoxyaluminum hydride. Lithium tri-/-butoxyaluminum hydride. Nickel-aluminum alloy. Pyridine-n-Butyllithium. Sodium amalgam. Sodium-Ammonia. Sodium borohydride. Sodium borohydride-BFs, see DDQ. Sodium dihydrobis-(2-methoxyethoxy) aluminate. Sodium hydrosulflte. Sodium telluride. Stannous chloride. Tin-HBr. Tri-n-butyltin hydride. Trimethyl phosphite, see Dinitrogen tetroxide. 

This reduction has been achieved previously with lithium triethoxyaluminum hydride (1,625). 

These relatively mild reducing agents can reduce the carbonyl of a lactone to give a lactol. In one example, 75 (an intermediate in Magnus synthesis of grandisol) was isolated in 97% yield when 74 was reduced with lithium triethoxyaluminum hydride at -20°C. It is known that trialkoxyaluminum hydrides will reduce aldehydes, ketones, esters and acid chlorides before reducing nitriles and amides. 

Nitriles can be reduced to amines by either catalytic hydrogenation or lithium aluminum hydride. However, the modified hydride reagent lithium triethoxyaluminum hydride adds to the bond only once to give an imine anion derivative. 

REDUCTION TO THE CORRESPONDING ALDEHYDE Lithium triethoxyaluminum hydride [LiAlH(OEt)j] was found to readily convert pseudoephedrine carboxamides to the corresponding aldehyde with only limited erosion of the ees (Table 2.5). To do so, a solution of the pseudoephedrine carboxamide in THF is added at -78°C to a suspension of LiAlH(OEt)j (2.3 equiv) in hexanes. The reaction mixture is then warmed to 0°C before a dilute acidic aqueous solution (typically HCl 0.5 M) is added, resulting in the formation of the desired aldehyde along with the pseudoephedrine aminal 27. To avoid the formation of the byproduct, the quenching can be performed using a 1M aqueous solution of hydrochloric acid and 10 equivalents of trifluoroacetic add. 

Several reduction methods are available to convert nitriles (Stephen reaction) or acyl chlorides (Rosenmund reduction) or amides to aldehydes. The use of lithium aluminum hydride at low temperatures or lithium triethoxyaluminum hydride appears to be a more effective means of reduction than the stannous chloride-HCl used in the Stephen method or palladium and hydrogen used in the Rosenmund reduction. 

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