128892-65-9

Upstream product

• 128892-60-4 methyl 5-benzyl-4-hydroxy-2-oxo-2,5-dihydro-1H-pyrrole-3-carboxylate 
• 7524-50-7 methyl (2S)-2-amino-3-phenylpropanoate hydrochloride 
• 13734-34-4 N-tert-butoxycarbonyl-L-phenylalanine 
• 112700-41-1 (5S)-5-benzyl-1-(tert-butyloxycarbonyl)-4-hydroxy-1,5-dihydro-pyrrol-2-one 
• 128892-59-1 sodium (5S)-5-benzyl-3-methoxycarbonyl-2,4-dioxopyrrolidine 
• 62973-00-6 2-(3-oxo-butyrylamino)-3-phenylpropionic acid methyl ester 
• 2113-89-5 (5S)-3-acetyl-5-benzyl-4-hydroxy-3-pyrroline-2-one 

Downstream Products

• 129029-33-0 (4R,5S)-5-Benzyl-4-hydroxy-2-oxopyrrolidine 
• 129029-32-9 (4S,5S)-5-Benzyl-2-oxo-4-hydroxypyrrolidine 

Relevant academic research and scientific papers

Cytotoxic tetramic acid derivative produced by a plant type-III polyketide synthase

The tetramic acid (2,4-pyrrolidinedione) scaffold has been recognized as an important structural feature because of its mycotoxic, antibacterial, antiviral, and antioxidant activities. This important class of natural products is reportedly produced by the type-I polyketide synthase/nonribosomal peptide synthetase (PKS/NRPS) hybrid megaenzyme systems. In contrast, the benzalacetone synthase (BAS) from Rheum palmatum is a structurally simple, plant-specific type-III PKS that catalyzes the one-step decarboxylative condensation of malonyl-CoA with 4-coumaroyl-CoA. The type-III PKS exhibits unusually broad substrate specificity and notable catalytic versatility. Here we report that R. palmatum BAS efficiently produces a series of unnatural, novel tetramic acid derivatives by the condensation of malonyl-CoA with aminoacyl-CoA thioesters chemically synthesized from l- and d-amino acids. Remarkably, the novel tetramic acid dimer d-5 formed from d-phenylalanoyl-CoA showed moderate antiproliferative activity against murine leukemia P388 cells.

Tetramic Acid Chemistry. Part 1. Reinvestigation of Racemisation during the Synthesis of Tetramic Acids via Dieckmann Cyclisation

Epimerisation during the synthesis of tetramic acids by Dieckmann cyclisation of the corresponding chiral N-acyl-α-amino esters was investigated.In the case of the isoleucine derivative, the extent of epimerisation was directly evaluated by 1H NMR analysis of the 3-acylated tetramic acids (3a,b) and (5a).A chemical correlation was carried out in the case of the 5-benzyl derivative (8h).The moderate overall yield and the partial epimerisation at position C-5 limit the usefulness of this approach for tetramic acid preparation.