The nitroimidazooxazine S-1 (PA-824) is a new class of bioreductive drug for tuberculosis. A series of related bicyclic nitroheterocycles was synthesized, designed to have a wide range of one-electron reduction potentials E(1) (from -570 to -338 mV, compared with -534 mV for S-1). The observed E(1) values closely correlated with the σm values of the heteroatom at the 4/8-position of the adjacen...

A connected graph of order n is bicyclic if it has n+1 edges. He et al. [C.X. He, J.Y. Shao, J.L. He, On the Laplacian spectral radii of bicyclic graphs, Discrete Math. 308 (2008) 5981–5995] determined, among the n-vertex bicyclic graphs, the first four largest Laplacian spectral radii together with the corresponding graphs (six in total). It turns that all these graphs have the spectral radius...

quinolones are a very important family of antibacterial agents that are widely prescribed for the treatment of infections in humans. since their discovery in the early 1960s, the quinolone group of antibacterials has generated considerable clinical and scientific interest. two major groups of compounds have been developed from the basic molecule: quinolones and naphthyridones. the 4-pyridone-3-...

'The development of a new, direct method for the preparation of dibenzo[a,e]cycloocta-1,5-dienes from phenylacetaldehyde by a double ortho Friedel-Crafts alkylation is described. When benzaldehyde (2b) is treated with trimethylsilyl iodide (3), a,n-diiodotoluene (6) is formed in high yield via the intermediacy of a-iodobenzyl trimethylsilyl ether (4b). Treatment of phenylacetaldehyde (%a) with ...

The enantioselective synthesis of 7-epi-incarvilline for formal syntheses of (-)-incarvilline, (+)-incarvine C, and (-)-incarvillateine is described. The key features of our synthesis involve (1) stereoselective construction of the optically active bicyclic lactone utilizing Pd(0)-catalyzed allylic alkylation, (2) efficient transformation of the bridged bicyclic lactone to the key bicyclic lact...

Reactions of the preformed cluster [(η(5)-C(5)Me(5))(2)Mo(2)(μ(3)-S)(4)Cu(2)(MeCN)(2)](ClO(4))(2) (1) with two tetraphosphine ligands, 1,4-N,N,N',N'-tetra(diphenylphosphanylmethyl)benzene diamine (dpppda) and N,N,N',N'-tetra(diphenylphosphanylmethyl)ethylene diamine (dppeda), produced two bicyclic clusters {[(η(5)-C(5)Me(5))(2)Mo(2)(μ(3)-S)(4)Cu(2)](2)(L)}(ClO(4))(4) (3: L = dpppda; 4: L = dppe...

The reaction of 2-functionalized 1-halo-2,n-enynes (n = 7 or 8) with a divalent titanium reagent, Ti(O-i-Pr)4/2i-PrMgCl, proceeded in a domino fashion to afford bicyclic compounds in good yields. © 2011 Elsevier Science. All rights reserved ——— * Corresponding author. Tel.: +81-45-481-5661; fax: +81-45-413-9770; e-mail: [email protected] We have recently developed a divalent titanium re...

Heterocyclic compounds are those cyclic compounds in which one or more of the ring carbons are replaced by another atom. The non-carbon atoms in such rings are referred to as ‘‘heteroatoms.’’ Such bicyclic heterocyclic compounds containing pyrrole ring with benzene ring fused to a,b-position are known as Indoles. Indole has a benzene ring and pyrrole ring sharing one double bond. It is a hetero...