Practical Synthesis of Pheromone Components of Achaea Janata (Noctuidae)

A practical synthesis of pheromone components of Achaea janata utilising double alkylations on TosMIC as key steps has been achieved.     

A formal total synthesis of crocacin C

An efficient total synthesis of a potent antifungal and moderate cytotoxic agent crocacin C is described. The synthesis involves the generation of four contiguous stereogenic centres via desymmetrization of a meso bicyclic dihydrofuran using asymmetric hydroboration.     

Stability of photocurable anhydrides: Methacrylic acid mixed anhydrides of nontoxic diacids

Disproportionation of the liquid mixed anhydride dimethacrylic sebacic anhydride (m‐SA) to methacrylic anhydride and polyanhydride oligomers, as well as vinylic polymerization, can occur on workup and storage at room temperature. Dimethacrylic 1,3‐bis(p‐carboxyphenoxy) propane, being a solid, can also disproportionate, but the propensity to do so is lower than for m‐SA. These events can be suppressed with free‐radical inhibitors, and the inhibitor 2+3‐t‐butyl‐4‐methoxyphenol is a more effective stabilizer than 4‐methoxyphenol at 20 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4189–4195, 2001     

Direct catalytic asymmetric method for the synthesis of tetrahydropyranopyrazoles through allene zwitterion chemistry

The enantioselective synthesis of the tetrahydropyranopyrazole scaffold has been achieved. The quinidine catalyzed reaction of allenoates with arylidenepyrazolones proceeded with high enantio- and diastereoselectivity while the reactions of alkylidenepyrazolones were less efficient. Allene ketones also afforded tetrahydropyranopyrazole derivatives in high yields, however, with only moderate enantioselectivity. The primary adduct undergoes further functional group transformations without effecting the initially formed chiral centre.     

Novel methodologies for the synthesis of functionalized lipophilic carboranes

Novel synthetic protocols for the synthesis of lipophilic carboranes were developed utilizing two C? C bond forming reactions, namely Baylis–Hillman and enynedioate cycloaddition reactions. Some of these carboranes were converted into further functionalized carboranes via nucleophilic allylic isomerization. Copyright © 2009 John Wiley & Sons, Ltd.     

Facile three-component domino reactions in the regioselective synthesis and antimycobacterial evaluation of novel indolizines and pyrrolo[2,1-a]isoquinolines

The domino reactions of pyridine/isoquinoline, bromoacetonitrile/ethyl bromoacetate and a series of β-nitrostyrenes in the presence of triethylamine afforded novel tri-/disubstituted indolizines and pyrrolo[2,1-a]isoquinolines regioselectively, presumably via substitution-dipole generation-1,3-dipolar cycloaddition-elimination and/or aromatisation sequence. In vitro screening of all the seventeen compounds synthesized against Mycobacterium tuberculosis H37Rv discloses that ethyl 2-(4-fluorophenyl)pyrrolo[2,1-a]isoquinoline-3-carboxylate displays maximum potency with minimum inhibitory concentration (MIC) of 1.0 μM, being 7.6 and 4.7 times more potent than the standard first line TB drugs, ethambutol and ciprofloxacin, respectively.     

Epibatidine and its analogues as nicotinic acetylcholine receptor agonist: an update

Epibatidine (EPB) (1), an alkaloid isolated from the skin of the Ecuadorian poison frog, Epipedobates tricolor has attracted attention because of its exceptionally powerful analgesic properties: several hundred times greater than those of morphine, and the fact that it acts at nicotine rather than opiate receptors. Although the substance is toxic, it does serve as a lead compound in the development of drugs for pain relief as well as treatment of disorders whose pathogenesis involves nicotinic receptors. In this article, isolation, synthetic methods, effect on neuronal and neuromuscular nicotinic receptors, therapeutic potential, toxicity, nicotinic pharmacophore structural modifications related issues of 1 are discussed.     

Progress in the research of artemisinin and its analogues as antimalarials: an update

Malaria is the number one infectious disease in the world today. Worldwide, over two million people die each year from malaria. This shocking reality is largely due to the emergence of drug resistant strains of Plasmodium falciparum. Artemisinin, a sesquiterpene lactone endoperoxide isolated from Artemesia annua has been shown to be a fast acting, safe and effective drug against multidrug-resistant and sensitive strains of P. falciparum. This article reports a survey of the literature dealing with artemisinin related antimalarial issues that have appeared from 1980s to the beginning of 2003. A broad range of medical and pharmaceutical disciplines is covered, including a brief introduction about discovery, phytochemical aspects, antimalarial mechanism of action, pharmacokinetics, and major drawbacks and various structural modifications made to overcome them.     

Stereoselective synthesis of functionalized pyroglutamates

Novel stereoselective synthesis of α-methylene-β-substituted pyroglutamates, and α-alkylidene-pyroglutamates has been achieved via substrate controlled asymmetric alkylation of l-threonine derived oxazole with Baylis-Hillman reaction based allyl bromides and acetates, respectively. The synthesized compounds were evaluated for their proteasome inhibition and cytotoxicity on multiple myeloma cells.     

Bis-spirochromanones as potent inhibitors of Mycobacterium tuberculosis: synthesis and biological evaluation

Molecular Diversity - On the basis of reported antimycobacterial property of chroman-4-one pharmacophore, a series of chemically modified bis-spirochromanones were synthesized starting from...