Current Organic Synthesis, Volume 1, Number 1, 2004
Contents
Synthesis of Anti-Angiogenic Isocoumarins Pp.1-9
Haiqing
Yuan, Bernd Junker, Paul Helquist and
Richard E. Taylor
[Abstract]
Useful Reactions in Modern Pheromone Synthesis Pp.11-29
Kenji
Mori and Takuya Tashiro
[Abstract]
Sialic Acid Donors: Chemical Synthesis and
Glycosylation Pp.31-46
Dino
K. Ress and Robert J. Linhardt
[Abstract]
Synthesis of Five- and Six-Membered Heterocycles
Through Palladium- Catalyzed Reactions
Pp.47-63
G.
Kirsch, S. Hesse and A. Comel
[Abstract]
Synthetic Studies on N-Methylwelwitindolinone C Isothiocyanate
(Welwistatin) and Related Substructures Pp.65-82
Carmen Avendano and J. Carlos Menendez
[Abstract] [Full text article]
Synthesis of 2,6-Dialkyl-1,2,5,6-Tetrahydropyridines
and Their Applications in Total Synthesis Pp.83-109
François-Xavier Felpin and Jacques Lebreton
Abstracts
[Back to top] Synthesis of Anti-Angiogenic Isocoumarins
Haiqing
Yuan, Bernd Junker, Paul Helquist and
Richard E. Taylor
[Full text article]
A concise synthetic route has been developed for the preparation of the naturally occurring isocoumarin cytogenin and NM-3, an analogue with anti-angiogenic activity. The route is general and also provided C(3) side chain modified analogues. Key aspects of the synthesis include orthogonal protection of the two aromatic alkoxy groups, benzylic lithiation and carboxylation, use of the resulting carboxylic acid in a DCC-promoted acylation of Meldrum’s acid, and facile ester enolate alkylations for introduction of side chains for convenient generation of a new set of NM-3 analogues.
[Back to top] Useful Reactions in Modern Pheromone Synthesis
Kenji
Mori and Takuya Tashiro
Various aspects of pheromone synthesis are reviewed by analyzing examples published between 1990 and early 2003. Syntheses executed with new methodologies such as organoborane reactions, organotransition metal chemistry including olefin metathesis, asymmetric epoxidation, asymmetric dihydroxylation, other asymmetric chemical processes, and stereoselective biocatalysis are selected to illustrate the usefulness of new reactions in pheromone synthesis.
[Back to top] Sialic Acid Donors: Chemical Synthesis and Glycosylation
Dino
K. Ress and Robert J. Linhardt
Sialic acids (or ulosonic acids) are a family of acidic ketoses (including neuraminic acid, KDN and KDO) that are found at the non-reducing terminus of many glycoconjugates. These saccharide residues are recognized ligands of protein lectins and are removed in the first step in glycoconjugate catabolism. Moreover, sialic acid containing carbohydrates, such as glycolipid gangliosides (i.e. GM3), glycopeptides (i.e. Tn) and polysaccharides (i.e. polysialic acid or colominic acid) play important biological roles. Thus, they represent important targets in natural product synthesis. This review examines the application of sialic acids as donors in glycosylation reactions. The synthesis of protected sialic acid donors and challenges associated with their use in the synthesis of heteronuclear and carbon glycosides are discussed.
[Back to top] Synthesis of Five- and Six-Membered Heterocycles Through
Palladium- Catalyzed Reactions
G.
Kirsch, S. Hesse and A. Comel
Over the last years, palladium-catalyzed coupling reactions have been extensively studied and the names of Heck, Stille, Suzuki and Sonogashira are well known for their contribution to this chemistry. Extension of the coupling reactions allowing introduction of heteroatoms have followed and the Buchwald-Hartwig reaction is now a concept for this chemistry.
Another achievement in this field is the possibility offered by the methodology to acceed to heterocyclic compounds either through a direct construction of the heterocyclic ring or by a two-step procedure (coupling followed by an heteroannulation).
We are in the following paper going to review these ways of preparing heteroaromatic compounds either as single ring system or condensed to other aromatic rings.
[Back to top]
Synthetic
Studies on N-Methylwelwitindolinone C Isothiocyanate (Welwistatin) and Related Substructures
Carmen Avendano and J. Carlos Menendez
[Full text article]
N-Methylwelwitindolinone C isothiocyanate (welwistatin), isolated from the blue-green alga Hapalosiphon welwitschii, is a potent MDR inhibitor. This review deals with synthetic efforts aimed at welwistatin itself or its fragments, together with work concerning the bicyclo[4.3.1]decane and cyclohepta[cd]indole systems, which are related to the CD and ABC fragments of the natural product.
[Back to top]
Synthesis
of 2,6-Dialkyl-1,2,5,6-Tetrahydropyridines and Their Applications in Total
Synthesis
François-Xavier Felpin and Jacques Lebreton
[Full text article]
This review focuses on the different approaches to construct the 2,6-dialkyl- 1,2,5,6-tetrahydropyridine skeleton and their applications in total synthesis of alkaloids.