2-Methylamino-l -

Deoxy-2-methylamino-L-glucose (N-methyl-i.-glucosamine) NHCH, HO HO H HOH2 C—C—C—C—C—CHO H H HO H the antibiotic streptomycin... 

Starting with two chiral centres, there should, therefore, be four stereoisomers, and this is nicely exemplified by the natural alkaloid (-)-ephedrine, which is employed as a bronchodilator drug and decongestant. Ephedrine is (li ,25)-2-methylamino-l-phenylpropan-l-ol, so has the structure and stereochemistry shown. 

IV- methy 1-L- gluco s amine (2-deoxy-2-methylamino-L-glucose)... 

The other component parts of streptomycin, namely L-streptose and the aminosugar 2-deoxy-2-methylamino-L-glucose (A -methyl-L-glucosamine), are also ultimately derived from o-glucose. Gentamicin Ci contains two aminosugars, L-garosamine and D-purpurosamine. 

From the 13C-NMR spectra of a series of 2-methylamino-l-phenyl-1 -propanol ephedrine analogs, it was established that the chemical shifts of C-l and C-3 are always 3-4 ppm smaller in the anti-than in the jvn-diastereomers363,364. This was explained by a greater number of gauche interactions in the energetically preferred anti conformation leading to a shielding of these two carbons. 

The chiral a-cyano allylamines prepared from ( )-3-phenylpropenal, potassium cyanide and (L)-ephcdrinc [(17 ,2S )-2-methylamino-l-phenylpropanol] hydrochloride as a mixture (1 1) of C-l epimers, were deprotonated using 2 equivalents of LDA in THF to give the dilithio compound37. Alkylation at C-3 afforded regioselectively a mixture of (E)- and (Z)-enamines in variable amounts depending on reaction conditions. Diastereoselectivity varied from moderate to excellent. Addition of HMPA and especially lithium iodide improved the diastereoselectivity. De-aggregation is proposed to be the reason for the effect of these additives. 

Both enantiomers of 2-methylamino-l-phenylpropanol (ephedrine, 1), which are commercially available and relatively inexpensive, have been used as auxiliaries in many syntheses of chiral compounds. Ephedrine can be used for amide alkylations both directly1-3, or as derived heterocyclic compounds (see Sections 1.1.1.3.3.4.2.1. and 1.1.1.3.3.4.2.2.). Acyclic derivatives of ephedrine are discussed in this section. For example, either enantiomer of ephedrine gives A-acylephedrines 2 in good yield without epimerization if treated with an anhydride at 65 °C for 10 minutes2. 

Aus Methylamino-essigsaure-ethylester (Sarkosin-ethylester) bzw. 2-Methylamino-l-oxo-l-phenyl-ethan werden mit Dithiocarbonsaure-cyanimid-dimethylester 4-Amino-5-methoxycar-bonyl-l-methyl-2-methylthio-imidazol bzw. 4-Amino-5-benzoyl-l-methyl-2-methylthio-imidazol hergestellt303. 

Die durch Cyclisierungen von 2-Aminocarbonyl-hydrazonen mit Natronlauge zuganglichen 5-Aryl(Hetaryl)-5-hydroxy-4-methyl-3-oxo-2,3,4,5-tetrahydro-l,2,4-triazine lagem sich mit Brom/Natriumacetat in 5-Aroyl(Hetaroyl)-2-methylamino-l, 3,4-oxadiazole um560. 

O HN, OCaH5 Tr 0 L1[AIH4]/THF 60° 2 h l-Hydroxy-2-methylamino-l-phenyl- propan (2 Diastereoisomere Ephedrin + Pseudoephedrin, 4 1) 93 5... 

METHYL-J MBDB EDEN 2-METHYLAMINO-l-(3,4-METHYLENEDIOXYPHENYL)BUTANE N-METHYL-1-(1,3-BENZODIOXOL-5-YL)-2-BUTANAMINE... 

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