Aluminum hydnde

Sodium borohydride (NaBH4) Lithium aluminum hydnde (L1AIH4)... 

Lithium aluminum hydnde reacts violently with water and alcohols so it must be used m solvents such as anhydrous diethyl ether or tetrahydrofuran Following reduc tion a separate hydrolysis step is required to liberate the alcohol product... 

Mescaline a hallucinogenic amine obtained from the peyote cactus has been synthesized in two steps from 3 4 5 trimethoxybenzyl bromide The first step is nucleophilic substitution by sodium cyanide The second step is a lithium aluminum hydnde reduction What is the structure of mescaline" ... 

The well-known reduction of carbonyl groups to alcohols has been refined in recent studies to render the reaction more regioselective and more stereoselective Per-fluorodiketones are reduced by lithium aluminum hydride to the corresponding diols, but the use of potassium or sodium borohydride allows isolation of the ketoalcohol Similarly, a perfluoroketo acid fluonde yields diol with lithium aluminum hydnde, but the related hydroxy acid is obtainable with potassium borohydnde [i f] (equations 46 and 47)... 

Studies of reductions with metal hydndes have concentrated on improvements in selectivity or conditions Replacement of the usual lithium aluminum hydnde-ether combination with potassium borohydride-methanol results m high yields of alcohol from ester [76] and less hazard [77] (equation 62) Reduction of a... 

Although isolated fluonne atoms can survive reductions with hthium aluminum hydnde when they are not m a position a to an ester or nitnle group [79] (equauons 63a and 63b), those in an a position arc reducti vely cleaved The milder borohydride reagents convert an a fluorocarboxylate ester to the corresponding alcohol without loss of fluonne [501 (equation 64)... 

The N A-difluoroammo substituent with no a-hydrogen is resistant to lithium aluminum hydnde [ester functions of polychlorofluorocarboxykUes to alcohols without loss of chlorine is accomplished with sodium borohydride [82] (equation 66)... 

DDB is presently available from Aldrich Chemical Company, Inc. For Its preparation, see the accompanying procedure Seebach, D. Kal-inowski, H -O. Langer, W. Crass, G., Wilka, E -M. Org. Synth. 1982, 61, previous prep 2097. DDB is hygroscopic and must be refluxed for some time and freshly distilled from lithium aluminum hydnde (bp 38°C/ 0.01 mm) pnor to use. The submitters used material with [a]n 14.7° the checkers sample showed [ajn 14.3°. 

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