23009-50-9

Upstream product

• 77120-56-0 C₈H₁₆ClNO₂ 
• 138512-74-0 1-tert-butyl 2-methyl (2S,4R)-4-methylpyrrolidine-1,2-dicarboxylate 
• 78-85-3 2-methylpropenal 
• 364750-80-1 (2S,4R)-1-[(tert-butoxy)carbonyl]-4-methylpyrrolidine-2-carboxylic acid 
• 61-90-5 L-leucine 
• 2743-60-4 L-Leucine ethyl ester 
• 165273-05-2 trans-4-methyl-L-proline ethyl ester 
• 1027101-89-8 N-CBz-trans-4-methyl-L-proline ethyl ester 
• 169820-06-8 N-CBz-4-exo-methylene-L-proline ethyl ester 
• 83507-89-5 N-<(phenylmethoxy)carbonyl>-4-oxo-(S)-proline ethyl ester 
• 103667-57-8 (2S,4R)-ethyl N¹-(benzyloxycarbonyl)-4-hydroxypyrrolidine-2-carboxylate 
• 61478-25-9 (2S,4R)-4-hydroxypyrrolidine-2-carboxylic acid ethyl ester 
• 51-35-4 4R-4-hydroxyproline 
• 119595-73-2 L-α-tert-butyl γ-methyl N-(9-(9-phenylfluorenyl))glutamate 

Downstream Products

• 333777-34-7 (2S,4R)-1-(((9H-fluoren-9-yl)methoxy)carbonyl)-4-methylpyrrolidine-2-carboxylic acid 
• 901139-63-7 N-9-fuorenylmethoxycarbonyl-(2S,4R)-4-methylprolyl-(2S,4S)-4-methylprolyl-glycine benzyl ester 
• 901138-97-4 N-9-fuorenylmethoxycarbonyl-(2S,4R)-4-methylprolyl-(2S)-prolyl-glycine benzyl ester 

Relevant academic research and scientific papers

Evolution of Biocatalytic and Chemocatalytic C-H Functionalization Strategy in the Synthesis of Manzacidin C

Because of their unique molecular architecture, the manzacidins have been the subject of intense synthetic efforts in the past two decades. Here, we describe two synthetic approaches toward manzacidin C that center on the enzymatic hydroxylation of unprotected l-leucine. This study also resulted in the discovery of novel synthetic methodologies, including a photocatalytic C-H azidation of unprotected amino acids. Additionally, we describe the use of hydroxylated l-leucine in the preparation of various densely substituted pyrrolidines.

A one-pot chemoenzymatic synthesis of (2S, 4R)-4-methylproline enables the first total synthesis of antiviral lipopeptide cavinafungin B

We report an efficient ten-step (longest linear sequence) synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (AT (Boc)G-Rink resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner. This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

Remote C-H Hydroxylation by an α-Ketoglutarate-Dependent Dioxygenase Enables Efficient Chemoenzymatic Synthesis of Manzacidin C and Proline Analogs

Selective C-H functionalization at distal positions remains a highly challenging problem in organic synthesis. Though Nature has evolved a myriad of enzymes capable of such feat, their synthetic utility has largely been overlooked. Here, we functionally characterize an α-ketoglutarate-dependent dioxygenase (Fe/αKG) that selectively hydroxylates the ? position of various aliphatic amino acids. Kinetic analysis and substrate profiling of the enzyme show superior catalytic efficiency and substrate promiscuity relative to other Fe/αKGs that catalyze similar reactions. We demonstrate the practical utility of this transformation in the concise syntheses of a rare alkaloid, manzacidin C, and densely substituted amino acid derivatives with remarkable step efficiency. This work provides a blueprint for future applications of Fe/αKG hydroxylation in complex molecule synthesis and the development of powerful synthetic paradigms centered on enzymatic C-H functionalization logic.

Nazumazoles A-C, cyclic pentapeptides dimerized through a disulfide bond from the marine sponge theonella swinhoei

A mixture of nazumazoles A-C (1-3) was purified from the extract of the marine sponge Theonella swinhoei. The mixture was eluted as an extraordinarily broad peak in the reversed-phase HPLC. The structures of nazumazoles were determined by interpretation o

Reciprocity of steric and stereoelectronic effects in the collagen triple helix

In previous work, we demonstrated that 4-fluoroproline residues can contribute greatly to the conformational stability of the collagen triple helix, and that this stability arises from stereoelectronic effects that fix the pucker of the pyrrolidine ring and thereby preorganize the backbone properly for triple-helix formation. Here, we take a reciprocal approach, demonstrating that the steric effect of a 4-methyl group confers stability similar to that from a 4-fluoro group in the opposite configuration. Such fundamental interplay between steric and stereoelectronic effects is heretofore unknown in proteinsnatural or syntheticand provides a new means to modulate conformational stability. Copyright

Isolation and structures of nostopeptolides A1, A2 and A3 from the cyanobacterium Nostoc sp. GSV224

The isolation and total structure determinations of nostopeptolides A1 (1), A2 (2) and A3 (3) are described. These cyclic depsipeptides, which are devoid of cytotoxic, antifungal and inhibition of protease activities, are characteristic constituents of the cryptophycin-producing cyanobacterium Nostoc sp. GSV224. Structure elucidation by NMR analysis was made more challenging by the existence of each nostopeptolide in three conformations. One-dimensional TOCSY experiments proved to be very useful in isolating and identifying the nine amino acid residues and the butyryl group in each compound. The absolute stereochemistries of 1-3 were determined by comparing the amino acids in the acid hydrolyzates directly with authentic standards. (C) 2000 Elsevier Science Ltd.

Asymmetric synthesis of 4-substituted prolines as conformationally constrained amino acid analogues

Treatment of readily available chiral building block 1 with (2R)-2,3-O- isopropylideneglyceraldehyde (5) provides a new route for asymmetric synthesis of 2,4-disubstituted pyrrolidines. Several proline-amino acid chimeras: proline-leucine, proline-lysine, proline-arginine and proline- glutamic acid, are synthesized in highly diastereomerically pure forms.

Synthesis of 4-Substituted Prolines as Conformationally Constrained Amino Acid Analogues

Anionic substitution of N-(9-(9-phenylfluorenyl))-protected glutamic acid esters proceeds without loss of optical integrity to give 4-substituted glutamic acid derivatives.The 4-methyl, propyl, cyanomethyl, and phenyl analogues have thus been prepared.Pri

Synthesis of Enantio- and Diastereoiso-merically Pure Substituted Prolines via Condensation of Glycine with Olefins Activated by a Carbonyl Group

The glycine fragment in the nickel(II) complex (1) formed from the Schiff's base of glycine and (S)-o-benzophenone (2) undergoes base-catalysed Michael addition to acrylaldehyde, α-methylacrylaldehyde, (E)-crotonaldehyde, (E)-cinnamaldehyde, and methyl vinyl ketone.No products of 1,2-addition were found in the Et3N-catalysed reactions.Addition followed by epimerization of the isomeric complexes proceeds with high diastereoselectivity at Cα (90percent) and Cβ of the corresponding amino acid side chains.After chromatographic separation, the diastereoisomerically pure complexes were decomposed and the resulting dihydropyrrole-2-carboxylic acids reduced with NaBH3CN to give (S)-proline, trans-3-methyl-(S)-proline, trans-5-phenyl-(S)-proline, and a mixture of cis- and trans-5-methyl-(S)-prolines.The chiral auxiliary (2) was recovered in 80-90percent yield.