From N-triisopropylsilylpyrrole to an optically active C-4 substituted pyroglutamic acid: total synthesis of penmacric acid

2009 ◽  
Vol 7 (21) ◽  
pp. 4512 ◽  
Author(s):  
Christophe Berini ◽  
Nadia Pelloux-Léon ◽  
Frédéric Minassian ◽  
Jean-Noël Denis
Keyword(s):  
Total Synthesis ◽  
Optically Active ◽  
Pyroglutamic Acid

Synthesis of Optically Active Hydroxyalkyl Cycloheptatrienes: A Key Step in the Total Synthesis of 6,11-Methylene-LXB4

Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 45-50
Author(s):  
Udo Nubbemeyer ◽  
Analuisa Nava ◽  
Lukas Trippe ◽  
Andrea Frank ◽  
Lars Andernach ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Total Synthesis ◽  
Structure Elucidation ◽  
Butyl Ester ◽  
Optically Active ◽  
Chiral Hplc ◽  
Reaction Conditions ◽  
Acid Product ◽  
Tert Butyl ◽  
Nabh4 Reduction

AbstractStarting from methyl cycloheptatrienyl-1-carboxylate, 6-acylation was successfully achieved employing glutaryl chloride in the presence of AlCl3 under controlled reaction conditions to furnish keto carboxylic acid product. After protection of this keto carboxylic acid as tert-butyl ester, reagent-controlled enantioselective reductions delivered configuration-defined methyl-6-hydroxylalkyl cycloheptatriene-1-carboxylates with up to 80% ee. Whereas simple NaBH4 reduction of the keto carboxylic acid and subsequent lactonization afforded a methyl-6-tetrahydropyranonyl cycloheptatriene-1-carboxylate. Resolution using chiral HPLC delivered the product enantiomers with up to >99% ee Finally, ECD analyses enabled structure elucidation. The products are used as key intermediates in enantioselective 6,11-methylene-lipoxin B4 syntheses.

ChemInform Abstract: Total Synthesis of Natural (+)-FR900482. Part 2. Efficient Syntheses of the Aromatic and the Optically Active Aliphatic Fragments.

ChemInform ◽  
2010 ◽  
Vol 27 (34) ◽  
pp. no-no
Author(s):  
T. YOSHINO ◽  
Y. NAGATA ◽  
E. ITOH ◽  
M. HASHIMOTO ◽  
T. KATOH ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Optically Active

ChemInform Abstract: Palladium-Mediated Asymmetric Synthesis of cis-3,6-Disubstituted Cyclohexenes. A Short Total Synthesis of Optically Active (+)-γ- Lycorane.

ChemInform ◽  
2010 ◽  
Vol 26 (34) ◽  
pp. no-no
Author(s):  
H. YOSHIZAKI ◽  
H. SATOH ◽  
Y. SATO ◽  
S. NUKUI ◽  
M. SHIBASAKI ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Optically Active

ChemInform Abstract: TOTAL SYNTHESIS OF OPTICALLY ACTIVE STEROIDS, XIV. SYNTHESIS OF ESTRADIOL

1976 ◽  
Vol 7 (43) ◽  
pp. no-no
Author(s):  
U. EDER ◽  
H. GIBIAN ◽  
G. HAFFER ◽  
G. NEEF ◽  
G. SAUER ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Optically Active

Synthesis of Optically Active 15-epi-9,14-Methylene Lipoxin A4

Synthesis ◽  
2018 ◽  
Vol 50 (06) ◽  
pp. 1246-1258
Author(s):  
Udo Nubbemeyer ◽  
Adile Duymaz ◽  
Jochen Körber ◽  
Carolin Hofmann ◽  
Dorothea Gerlach
Keyword(s):  
Total Synthesis ◽  
Building Block ◽  
Building Blocks ◽  
Optically Active ◽  
Protecting Groups ◽  
Lipoxin A4 ◽  
Methylene Bridge ◽  
Type Coupling ◽  
Important Field ◽  
Gain Access

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.

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