Absolute Configuration of 3-Amino-2-methylpropanol

It is known that natural (-)-2-methylbutanol, a convenient r eference standard for branched-chain structures, has the configuration F. 3-Amino-2-methylpropanol can also b e useful for correlations of branchedchain compounds

Preparation of Peptide-like 2,5-Disubstituted p-Benzoquinone Derivatives. Peptide-like Polyoxo Compounds

A description is given of the reaction products of p-benzoquinone with glycine benzyl ester [lc], with B-alanine ethyl ester [Id] and with glycylglycine ethyl ester [le]

Pseudoconhydrine; Direct Correlation of the Configuration at C(2) with that of α-Amino Acids

(+)-B-Amino-n-caproic acid, obtained by oxidation of pseudoconhydrine, was prepared by stereospecific synthesis from L-norvaline which showed that this acid is of the configuration III, and pseudoconhydrine of the configuration IV

Configuration of ( + )-Dihydrothymine and Related Compounds

A description of the preparation of (-)-~-ureidoisobutyric acid (III) and (+)-dihydrothymine (IV) from (-)-~-aminoisobutyric acid is given. (-)-2,6-Dioxo-4-propylhexahydropyrimidine (VI) was prepared from L-~-amino-n-caproic acid. Optically active III, IV, and VI are new compounds, and evidence is presented for their absolute configuration

Synthesis of β-Phenyl-α,β-dioxo-propionanilide. Peptide-Like Polyoxo Compounds

In the first communication of this series it was shown that 2,3,4-triketotetrahydropyridine exercises a diaibetogenic activity on white rats, the same as alloxane. It, was, further, suggested, fill.at the grouping -COCOCONH- may be responsible for this activity of 2,3,4-triketo-tetrahydropyridine, as for that of alloxane

A Route for the Synthesis of Substituted Dioxene Derivatives

In our work on muscarine, certain quaternary ammonium salts with the substituted 1,4-dioxane nucleus were necessary for studies on biological activity. For this purpose we followed a new synthetic route for the preparation of substituted 1 , 4-dioxene derivatives, according to the reaction scheme I-IV

Synthesis of the Homologue of L-Leucine (Synthesis of-β-Amino-D-methyl-caproic Acid)

It has been shown that N-Phthalyl-derivatives of a-amino- acids can be converted into the corresponding diazoketones. We have applied this reaction to the preparation of the homologue of L-leucine by the Arndt-Eistert synthesis from the hitherto undescribed diazoketone of N-phthalyl-L-leucine (I), Methanolic solution of (I) heated with silver oxyde yielded the optically active ester of the homologous acid (Il), which, refluxed with hydriodic acid, gave the free, optically active B-amino acid (III)

Synthesis of Aminoalkylglyoxal Derivatives III. Aminoalkylglyoxal Derivatives of α-Aminobutyric Acid and Valine*

Starting from DL-a-aminobutyric acid and DL-v a line the corresponding aminoalkylglyoxals VIIa and VIIb were prepared by Krohnke\u27s method , through the reaction stages II-VII. Further, a description is given of the pireparation of DL-1-acetoxy-3-phthalim idorpent an- 2-one, and of the conversion of the glyoxal VIIa into the 1, 1-diethylacetal VIIIa, the hydroxyacetal IXa, and the a-glycol Xa, which are useful intermed iates for the synthesis of compounds of the type I. The aldehyde group of these glyoxals readily reacts with N,N-diphe n yl-1,2-dia minoethane, affording condensation products XI. Quinoxaline and bisethylenemerc aptal derivatives of the glyoxals VII were also prepared. Improved pireparations are described for DL- a - amino butyric acid and the corresponding phthalimido derivative