Current Organic Synthesis - Volume 10, Issue 1, 2013

Natural products play an important role as a source not only of potential therapeutic drugs but also of starting materials for semisynthetic new medicines. The epoxyquinoid family, composed by cyclohexane epoxides and related structures, exhibit these characteristics without doubt. Since 2004, significant efforts have been devoted to the stereocontrolled synthesis of these molecules with different and interesting strategies Read More

Olefin metathesis has become a useful method in organic synthesis, rivaling palladium catalyzed C-C bond forming reactions as well as more traditional olefination processes. Olefin cross metathesis (CM) emerged later than ring closing metathesis and ring opening metathesis polymerization due to poor selectivity control. However, after the discovery of more active second generation catalysts and elaboration Read More

(+)-Jasplakinolide (jaspamide) is a 19-membered depsipeptide identified from the marine sponge in 1986. It features with a macrolactam joined by a tripeptide unit and a non-peptide polypropionate sector containing three chiral centers. Along with the common acid L-alanine, jasplakinolide contains an unnatural D-amino acid 2-bromoabrine and the rare (R)-β-tyrosine. The unique and complex structure, as well as the remar Read More

Cu(I)-catalyzed click reaction, a set of powerful and virtually reliable 1,3 dipolar cycloaddition of organic azide and terminal alkyne, has been extensively used in adjoining two entirely different building blocks, enabling an easy access of complex molecular-level architectures, which find exponentially expanding application in diverse disciplines of science ranging from organic synthesis, material sciences, combinatorial ch Read More

The present review summarizes the synthetic strategies to functionalized bridgehead nitrogen heteroannulated 1,2,4-triazine systems as well as their regiospecific and pharmacological properties.

An efficient Pd(PPh3)4/2,5-norbornadiene-catalyzed cycloaddition of 1,4-disubstituted 1,3-butadiynes with H2O under basic conditions for straightforward and simple synthesis of 2,5-disubstituted furans is described.

Nitration of δ-tocopherol (1) with either concentrated nitric acid or with nitrating agents in the presence of oxidants provides 5-(7'-nitro-δ-tocopher-5'-yl)-7-nitro-δ-tocopherol [bis(7-nitro-δ-tocopheryl), 6]. Under non-oxidative conditions, the 5-nitro and 5,7- dinitro products of δ-tocopherol are formed without production of 6. The dimer 6 is C2-symmetric and shows unrestricted rotation around the 5-5' bond and a strong hydrog Read More

The regioselectivity in the ring opening of epoxides with various nucleophiles has been investigated in depth using quantum mechanical methods. Alkylepoxides are attacked regioselectively at their less substituted side, controlled by the steric effect, while aryl/alkenylepoxides show alterable regioselectivities, regulated by a combined action of the steric hindrance and the electronic effect of aryl and alkenyl groups, impacted Read More

A concise chemical synthesis of the common tetrasaccharide corresponding to the O-antigen of enteroinvasive Escherichia coli O143 and Shigella boydii type 8 has been achieved in excellent yield. Application of [2+2] block glycosylation and late stage oxidation of primary hydroxyl groups to the carboxylic groups are notable features in the synthetic strategy.