19/12/2017 · Request (PDF) | Synthesis, Isomer Ch ..

T1 - Stereoselective total synthesis of the E-isomer of putative lucentamycin A

03/01/2017 · Synthesis of a regio-isomer of ..

2,3-Methanoamino acids are useful probes for studying the bioactive conformation of peptides and for investigating the effect of local conformational constraints on the activity of peptidomimetics. We synthesized all four stereoisomers of Cbz-protected 2,3-methanoleucine for incorporation into peptidomimetic inhibitors of calpain. While the synthesis of 2,3- methanoamino acids has been previously reported, our procedure offers a versatile route in which the pair of diastereomers of each geometric isomer was synthesized from a common intermediate. (C) 2000 Wiley-Liss, Inc.

Citronella (Citric acid) | Organic Synthesis | Isomer

N2 - 2,3-Methanoamino acids are useful probes for studying the bioactive conformation of peptides and for investigating the effect of local conformational constraints on the activity of peptidomimetics. We synthesized all four stereoisomers of Cbz-protected 2,3-methanoleucine for incorporation into peptidomimetic inhibitors of calpain. While the synthesis of 2,3- methanoamino acids has been previously reported, our procedure offers a versatile route in which the pair of diastereomers of each geometric isomer was synthesized from a common intermediate. (C) 2000 Wiley-Liss, Inc.

Syntheses of R-salbutamol froma racemic mixture:A cheap and easy way to make R-salbutamol is to synthesis a racemicmixture and separate the isomers (either at an intermediate stage or ofthe final products).


Ligand Design for Isomer-Selective Oxorhenium(V) Complex Synthesis

Salbutamol:



Due to the dramatically different biological activity of the two differentoptical isomers of salbutamol the synthetic routes reported in the literatureconcentrate on the synthesis of R-salbutamol.

Synthesis and isomer distribution of 2-alkyltropinones …

A synthesis of the E-isomer of the proposed structure of the novel tripeptide, lucentamycin A, was performed in an attempt to define the correct stereochemistry of this natural product. The synthetic route developed employs a stereoselective Rh-catalyzed reductive cyclization process to generate the key pyrrolidine residue in the target and a stereospecific inversion of the Z-olefin geometry to form desired E-isomer. Subsequent amide coupling reactions afforded the desired E-isomer of putative lucentamycin A. A comparison of the NMR data of synthetic E-1a with that of the naturally occurring lucentamycin A demonstrated that they are not identical substances and the E-1a was found to display no anti-proliferative activity on the colon cancer cell line HCT-116 in contrast to natural lucentamycin A.

Communications - Synthesis of an Isomer of …

N2 - Lipase-catalyzed enantioselective lactonization of racemic methyl 6-phenyl-4-hydroxy-5-hexynoate worked well to afford (R)-6-phenyl-5-hexyn-4-olide (42% yield, 81% e.e.). The e.e. of the product was enhanced to 97% by the repetition of enzymatic reaction. From this lactone, (4R,5R)-isomer of 5-hydroxy-6-phenyl-4-hexanolide, a lateral root inducing substance from Erwinia quercina was synthesized via a selective epoxidation of the intermediate and subsequent hydrogenolysis as the keystep.

Synthesis of batzelladine E and its E isomer - …

AB - Lipase-catalyzed enantioselective lactonization of racemic methyl 6-phenyl-4-hydroxy-5-hexynoate worked well to afford (R)-6-phenyl-5-hexyn-4-olide (42% yield, 81% e.e.). The e.e. of the product was enhanced to 97% by the repetition of enzymatic reaction. From this lactone, (4R,5R)-isomer of 5-hydroxy-6-phenyl-4-hexanolide, a lateral root inducing substance from Erwinia quercina was synthesized via a selective epoxidation of the intermediate and subsequent hydrogenolysis as the keystep.

The syntheses of an isomer of kotalanol, a naturally occurring ..

N2 - A synthesis of the E-isomer of the proposed structure of the novel tripeptide, lucentamycin A, was performed in an attempt to define the correct stereochemistry of this natural product. The synthetic route developed employs a stereoselective Rh-catalyzed reductive cyclization process to generate the key pyrrolidine residue in the target and a stereospecific inversion of the Z-olefin geometry to form desired E-isomer. Subsequent amide coupling reactions afforded the desired E-isomer of putative lucentamycin A. A comparison of the NMR data of synthetic E-1a with that of the naturally occurring lucentamycin A demonstrated that they are not identical substances and the E-1a was found to display no anti-proliferative activity on the colon cancer cell line HCT-116 in contrast to natural lucentamycin A.