S -4-Anilino-3-methylamino-1 -butanol

Stereoselective Alkylation. Chiral tricyclic lactams can be prepared from (l/ ,2/ ,35,5/ )-ATBH and y-keto acids by heating in toluene with a catalytic amount of p-toluenesulfonic acid (eq 7). Enolization of the resulting lactams with sec-butyllithium, followed by trapping with methyl iodide, furnishes the methylated products in high diastereoselectivity. Subsequent enolization and alkylation with benzyl bromide affords a single diastereomer in 82% yield. Further acidic hydrolysis in butanol provides the desired ester with a quaternary asymmetric center (eq 7).  

Moriyasu Masui Aburahi Laboratories, Shionogi Co., Ltd., Japan 

Preparative Methods p-benzyl 7V-benzyloxycarbonyl-aspartate is treated with ethyl chloroformate, N-methymorpholine, and aniline. Subsequent reduction of the corresponding anilide with LiAlHq gives the title reagent in overall 80% yield.  

Chiral Ligand of L1A1H4 for the Enantioselective Reduction of Alkyl Phenyl Ketones. Optically active alcohols are important synthetic intermediates. There are two major chemical methods for synthesizing optically active alcohols from carbonyl compounds. One is asymmetric (enantioselective) reduction of ketones. The other is asymmetric (enantioselective) alkylation of aldehydes. Extensive attempts have been reported to modify Lithium Aluminum Hydride with chiral ligands in order to achieve enantioselective reduction of ketones. However, most of the chiral ligands used for the modification of LiAlHq are unidentate or bidentate, such as alcohol, phenol, amino alcohol, or amine derivatives. 

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ASYMMETRIC REDUCTION, OF KETONES Darvon alcohol. NB-Enantrene. NB-Enantride. Lithium aluminum hydride-(S)-4-Anilino-3-methylamino-1 -butanol. B-3-Pinanyl-9-borabic y clo 13.3.1 Jnonane. 

Amino-2-methyIpropanenitrile, 173 (S)-2-Aminopropyl benzyl ether, 30 2-Aminoletralin, 346, 347 (S)-4-Anilino-3-methylamino- 1-butanol, 292-... 

ASYMMETRIC REDUCliON OF KETONES (S)-(—)-2-Amino-3-tHethyI-1,1 -diphenyl-butane- I -ol. (S)-4-Anilino-3-methylamino-I -butanol. 2,2-Dihyd(oxy-1,1 -binaphthyl. 

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