Optically Active Functionalized Building Blocks for Peptidyl Olefin Peptidomimetics

2021 ◽  
Vol 6 (31) ◽  
pp. 7912-7918
Author(s):  
Ekaterina Lerman ◽  
Shlomo Levinger ◽  
Amnon Albeck
1989 ◽  
Vol 42 (1) ◽  
pp. 17-29 ◽  
Author(s):  
Tomoya Kitazume ◽  
Takeshi Ohnogi ◽  
Jenq Tain Lin ◽  
Takashi Yamazaki ◽  
Keizo Ito

Synthesis ◽  
2018 ◽  
Vol 50 (06) ◽  
pp. 1246-1258
Author(s):  
Udo Nubbemeyer ◽  
Adile Duymaz ◽  
Jochen Körber ◽  
Carolin Hofmann ◽  
Dorothea Gerlach

The synthesis of lipoxin A4 and B4 analogues (LXA4, LXB4) to gain access to stabilized inflammation resolving compounds is an important field of research. Starting from known structural requirements of the natural compounds displaying biological activity and a broad investigation of their rapid metabolism, various LXA4 derivatives have been developed and tested. Focusing on variation and stabilization of the conjugated E,E,Z,E C7–C14 tetraene moiety of natural LXA4, a methylene bridge introduced between C9 and C14 might suppress any Z/E isomerization of the C11–C12 olefin. Intending to enable at least known structure variations in connection with the C1–C7 and the C15–C20 fragments, a convergent total synthesis starting from a known cycloheptatriene is developed. The C1–C8 building blocks are generated via six-step ex-chiral pool sequences starting from 2-deoxy-d-ribose delivering two 5,6-dihydroxy carboxylic acid derivatives with C7 aldehyde functions. The synthesis of the C8–C21 building block starts from a known cycloheptatriene 1-carbonester (C8–C14, C21) and hexanoyl chloride (C15–C20). After Friedel–Crafts-type coupling, the defined configuration of the C15 OH group is introduced via enantioselective reduction of the ketone precursor. Following an additional four steps, an aryl sulfone C9–C21 building block is completed ready for a key Julia–Kocienski olefination with the C1–C7 compounds. Finally, removal of the protecting groups completes the synthesis of the target optically active 9,14-methylene LXA4 methyl ester.


1991 ◽  
Vol 56 (25) ◽  
pp. 7177-7179 ◽  
Author(s):  
Sadao Tsuboi ◽  
Junichi Sakamoto ◽  
Takayuki Kawano ◽  
Masanori Utaka ◽  
Akira Takeda

2002 ◽  
Vol 80 (6) ◽  
pp. 686-691 ◽  
Author(s):  
Nicole Diedrichs ◽  
Ralf Krelaus ◽  
Ina Gedrath ◽  
Bernhard Westermann

Enantiomerically enriched oximes bearing stereogenic quaternary carbon centers can be obtained by lipase-catalyzed kinetic resolution of oxime esters. Substrate specificity, solvent effects, and the use of different lipases are discussed. Kinetic resolution of butyrylated oximes by lipase PS in the presence of n-butanol gave the best ee-values of both the saponified oxime and the residual oxime ester. Subsequent stereospecific Beckmann rearrangement of an enantiomerically enriched oxime provided lactams, which could be employed for the synthesis of optically active perhydro histrionicotoxin.Key words: oxime, lipase, kinetic resolution, Beckmann rearrangement, perhydro histrionicotoxin.


The field of biotransformations has developed rapidly over the past eight years. The use of esterases and lipases is now widespread; these enzymes are of particular importance in the production of optically active building blocks for organic synthesis as well as in large-scale processes involving the transesterification of fats. The latter area (i.e. the catalysis of esterification processes) has stimulated research into the properties of immobilized enzymes and the use of enzymes in low-water systems. In related work, enzymes have been used for the preparation of peptides and small proteins. Redox enzymes have been investigated extensively, particularly with regard to the stereocontrolled reduction of ketones to secondary alcohols. The methods for using commercially available enzymes of this type have become increasingly ‘userfriendly’. The controlled oxidation of hydrocarbon units is another area that has deserved increased attention. For example, oxidation of benzene and simple derivatives by Pseudomonas sp. has been researched by a number of U.K. groups. These recent advances in enzyme-catalysed reactions (using both whole-cell systems and partly purified protein) for the transformation of unnatural substrates is discussed and some areas of interest for the future are outlined.


ChemInform ◽  
1988 ◽  
Vol 19 (40) ◽  
Author(s):  
D. G. DRUECKHAMMER ◽  
C. F. III BARBAS ◽  
K. NOZAKI ◽  
C.-H. WONG ◽  
C. Y. WOOD ◽  
...  

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