A few facile synthetic pathways for bicyclic aminopyridinol antioxidants are presented. Attachment of a long alkyl chain to the bicyclic pyridinol scaffold was established using ester linkage. Non-substituted pyrrolopyridinols and 1,3-oxazine-fused pyridinols were also synthesized as novel antioxidant scaffolds. Antioxidant activities were measured by a radical clock method and new compounds pr...

let $r$ be a commutative ring. in this paper, by using algebraic properties of $r$, we study the hase digraph of prime ideals of $r$.

The molybdenum-mediated cleavage reactions of isoxazoline rings fused in bicyclic frameworks were investigated. A tandem N-O bond cleavage-retro aldol reaction of an isoxazoline ring fused in a bicyclic framework led to the cleavage of the bicyclic framework. These reactions provide a novel stereoselective synthesis of substituted cyclopentene rings, cyclopentane rings, and attached-ring system...

In this note, we give a characterization of the adjacency matrix of the line digraph of a regular digraph and we discuss a generalization.On the light of the characterization given, we remark that the underlying digraph of a coined quantum random walk is the line digraph of a regular digraph. 1. A characterization of the adjacency matrix of the line digraph of a regular digraph 1.1. Set-up. The...

Bicyclic peptides are promising scaffolds for the development of inhibitors of biological targets that proved intractable by typical small molecules. So far, access to bioactive bicyclic peptide architectures is limited due to a lack of appropriate orthogonal ring-closing reactions. Here, we report chemically orthogonal ring-closing olefin (RCM) and alkyne metathesis (RCAM), which enable an eff...

A domino reaction has been developed for the synthesis of oxygen bridged bicyclic ethers through the coupling of 4-(2-hydroxyethyl)cyclohex-3-enols with aldehydes in the presence of 10 mol% of molecular iodine in dichloromethane at 25 °C. This method is highly diastereoselective affording the corresponding bicyclic ethers, i.e. octahydro-4a,7-epoxyisochromenes in good yields with high selectivi...

The fragmentation reaction of differently functionalized [2.2.2]- and [2.2.1]bicyclic systems that leads to substituted five membered heterocycles and five/six membered carbocycles is broadly studied. This reaction is carried out through a retro-Dieckmann-type condensation on strained [2.2.1]bicyclic β-ketosulfones and their counterparts β-ketoesters under very mild catalytic acid or basic cond...

Bicyclic graphs are connected graphs in which the number of edges equals the number of vertices plus one. In this paper we determine the graph with the largest spectral radius among all bicyclic graphs with n vertices and diameter d. As an application, we give first three graphs among all bicyclic graphs on n vertices, ordered according to their spectral radii in decreasing order. © 2006 Elsevi...

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...