39897-05-7

Upstream product

• 70-26-8 D-ornithine 
• 501-53-1 benzyl chloroformate 
• 16682-12-5 D-ornithine hydrochloride 

Downstream Products

• 69677-01-6 ((R)-4-Benzyloxycarbonylamino-6-diazo-5-oxo-hexyl)-carbamic acid benzyl ester 
• 60242-84-4 (R)-N,N-dibenzyloxycarbonyl-β-lysine methyl ester 
• 69677-00-5 ((R)-4-Benzyloxycarbonylamino-4-chlorocarbonyl-butyl)-carbamic acid benzyl ester 
• 2387-23-7 1,3-Dicyclohexylurea 
• 69677-16-3 [N'-((R)-3,6-Bis-benzyloxycarbonylamino-hexanoyl)-N-phenyl-hydrazino]-acetic acid ethyl ester 
• 69677-17-4 [N'-((R)-3,6-Bis-benzyloxycarbonylamino-hexanoyl)-N-phenyl-hydrazino]-acetic acid 
• 60242-85-5 [N'-((R)-3,6-Bis-benzyloxycarbonylamino-hexanoyl)-N-methyl-hydrazino]-acetic acid ethyl ester 
• 69677-10-7 (R)-3,6-Dibenzyloxycarbonylaminohexanoylsarcosinethylester 
• 60242-87-7 [N'-((R)-3,6-Bis-benzyloxycarbonylamino-hexanoyl)-N-methyl-hydrazino]-acetic acid 
• 64934-04-9 (R)-3,6-Dibenzyloxycarbonylaminohexanoylsarcosin 
• 69677-19-6 (R)-3,6-Dibenzyloxycarbonylaminohexanoicacidhydrazid 

Relevant academic research and scientific papers

Differentiation Among the Four Diastereomers of Benzyloxycarbonyl-protected γ-Hydroxyornithine in Negative-ion Fast Atom Bombardment Mass Spectrometry

Discrimination among the four γ-hydroxyornithine diastereomers was studied by fast atom bombardment mass spectrometry (FABMS).It is impossible to distinguish among the four diastereomers of this amino acid by positive- and negative-ion FAB and collisionally activated dissociation MS, but benzyloxycarbonyl group protection of the α- and δ-amino groups in γ-hydroxyornithine allows differentiation among the diastereomers in negative-ion FABMS.The negative-ion mass spectra of benzyloxycarbonyl-protected γ-hydroxyornithine diastereomers showed differences among the abundances of the molecule ion (-), the dehydrated ion (-) due to the loss of the γ-hydroxyl group and the fragment ions formed from both (-) and (-) ions.On the other hand, no difference was found between the fragmentations of the benzyloxycarbonyl-protected enantiomers of ornithine in negative-ion FABMS.These results indicate that the orientation of the γ-hydroxyl group and the existence of two benzene rings in the benzyloxycarbonyl group are important factors which are responsible for the fragmentations of the four benzyloxycarbonyl-protected γ-hydroxyornithine diastereomers in negative-ion FABMS.These studies also showed that the negative-ion FABMS for benzyloxycarbonyl-protected γ-hydroxyornithine diastereomers is a useful method for determining the configuration of each diastereomer of γ-hydroxyornithine.

Asymmetric Syntheses of the Naturally Ocurring β-Amino Acids, β-Lysine, β-Leucine and β-Phenyl-β-alanine via Nitrone Cycloaddition

A general asymmetric synthesis of β-amino acids is based on the dipolar cycloaddition of nitrones 7 (R* chiral) with vinyl acetate 8a, ketene acetals 8b or α-chloroacrylonitrile 8c.The cycloadducts 9 are converted either directly (9b) or via the isoxazolidones 10 (9a, 9c) into the free β-amino acids 11.Diastereoselectivity at C-3 in the adducts 9 ranges between 2:1 and 11:1.The natural β-amino acids, β-lysine, β-leucine and β-phenyl-β-alanine, have been prepared in this way.