Elucidation of the chemo- and stereoselectivity of [1+2] cycloaddition reactions between -cis-himachalene and dichlorocarbene using a multiphilic descriptor

A theoretical study of the mechanism and selectivity of [1+2] cycloaddition reactions between a-cis-himachalene and dichlorocarbene was performed using DFT B3LYP/6-311+G(d, p). Analysis of the global electrophilicity indeces shows that a-cis-himachalene behaves as a nucleophile, while dichlorocarbene behaves as an electrophile. In line with the local philicity concept, we propose a multiphilic descriptor. This descriptor is capable of simultaneously explaining the nucleophilicity and electrophilicity of the atomic sites in the molecule. The double bond of the six-membered ring is attacked when stoichiometric quantities of a-cis-himachalene and dichlorocarbene are used, while the other double bond is attacked by dichlorocarbene only when it is used in excess. The calculation of activation and reaction energies indicates that the a cycloadducts are favored both kinetically and thermodynamically

Passive observation-based architectures for management of web services

Web Services technologies are emerging as the standard paradigm for program-to-program interactions over the Internet. A Web Service is any application that offers its functionalities through the Internet by publishing a description of its interfaces. Web Services are gaining more and more momentum and their utilization is being spread and even standardized in many areas including e -Government, e -Telecomm, e -Health, and digital imaging. The management of Web Services will play an important role for the success of this emerging technology and its adoption by both providers and consumers. As the technology matures and spreads, consumers are likely to be very picky and restrictive with regards to the quality of the offered Web Services. Another challenging factor for the management of Web Services is related to the diversity of platforms on which Web Services are developed and deployed. In this thesis, the focus is on the management of Web Services using passive observation with the intent to have open and platform-independent management architectures capable of assessing both functional and non-functional aspects of Web Services. The bulk of the observation process is carried out by model-based entities known as observers. These observers make use of formal model such as Finite State Machines, Communicating Finite State Machines, and Extended Finite State Machines. The proposed architectures include observers developed and deployed as Web Services: mono-observer architecture and multi-observer architectures. A single observer is enough for observation of a non-composite Web Service while a network of observers is preferred when observing a composite Web Service. Passive observation requires traces' collection mechanisms which are thoroughly studied and their performance compared for all architectures. A new approach for online observation based on Extended Finite State Machine is proposed to accelerate misbehaviors' detection. This approach proposes backward and forward walks in the model to reduce possible sets of states and values of variables. I adopted a pragmatic evaluation approach to assess each of my contributions: analytical analysis and proof, implementation, and real case studies. All components of management architectures have been studied, their complexities determined, developed, and deployed. The use cases used for the evaluation of the effectiveness of the architecture, including simple and composite Web Services, are also fully implemented and deployed

Service oriented centered e-health solution for monitoring and preventing chronic diseases

The modern and continuously changing lifestyles in almost all parts of the world resulted in an increase in the incidence of chronic diseases (CDs). To reduce risks associated with chronic diseases, health professionals are studying various clinical solutions. As a result of recent advances in sensing technology, wireless communications, and distributed communication, the monitoring of patients\u27 health condition and the elaboration of prevention plans are considered the most promising solutions for the treatment of chronic diseases. In this paper, we propose a novel framework for monitoring chronic diseases and tracking their vital signs. The framework relies on the service orientation concepts and standards to integrate various subsystems. Monitoring of subjects\u27 health condition, using various sensors and wireless devices, aims to proactively detect any risk of chronic diseases. The system will allow generating and customizing preventive plans dynamically according to the subject\u27s health profile and context while considering many impelling parameters. As a proof of concept of our monitoring and tracking schemes, we have considered a case study for which we have collected and analyzed preliminary data

(1S,2S,4R)-3,3-Dichloro-4,8,12,12-tetra­methyl­tricyclo­[5.5.0.02,4]dodeca-6,8-diene

The title compound, C16H22Cl2, a derivative of β-himachalene, was semi-synthesized from natural essential oils of Cedrus atlantica. The mol­ecule is built up from two fused six- and seven-membered rings. The six-membered ring has a perfect chair conformation, whereas the seven-membered ring displays a screw boat conformation; the dihedral angle between the rings is 46.48 (9)°

The regio- and stereoselective addition of dibromocarbene and dichlorocarbene onto β-himachalene

In this work we used DFT B3LYP/6-31G (d) to study the mechanism, the regio- and stereoselectivity of the [1+2] cycloaddition reaction between β-himachalene and dihalogenocarbene. Analysis of the reactivity indices and calculation of the activation energies of the transition states showed that this reaction is stereoselectives, the treatment of β-himachalene with one equivalent of dibromocarbene leads via an exothermic reaction to the formation of a single product P1 resulting from the attack of the most substituted double bond C6=C7 of β-himachalene. Treatment of product P1 with one equivalent of dichlorocarbene leads, again via an exothermic reaction, to formation of the two products P3 and P4, but dibromocarbene does not react with the product P1 due to the high activation energy of this reaction

12-{[4-(2-Fluoro­phen­yl)piperazin-1-yl]­meth­yl}-9α-hy­droxy-4,8-dimethyl-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one

The title compound, C25H33FN2O4, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methyl­ene-3,14-dioxatricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The asymmetric unit contains two independent mol­ecules. In each mol­ecule, the ten-membered ring displays an approximative chair–chair conformation. Each of the piperazine rings adopts a perfect chair conformation, while both lactone rings show an envelope conformation, one with the C atom bearing the piperazin-1-ylmethyl group as the flap, the other with the junction C atom not attached to the ring O atom as the flap. The dihedral angles between the least-squares planes through the ten- and five-membered rings in the two mol­ecules are similar [19.1 (3) and 16.2 (3)°]. An intra­molecular O—H⋯N hydrogen bond stabilizes the mol­ecular conformation. The crystal packing is stabilized by C—H⋯O hydrogen bonds

10α-Hy­droxy-13-{[4-(4-meth­oxy­phen­yl)piperazin-1-yl]meth­yl}-4,9-dimethyl-3,8,15-trioxatetra­cyclo­[10.3.0.02,4.07,9]penta­decan-14-one

The title compound, C26H36N2O6, was synthesized from 9α-hy­droxy­parthenolide (9α-hy­droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo­[9.3.0.02,4]tetra­dec-7-en-13-one), which was isolated from the chloro­form extract of the aerial parts of Anvillea radiata. The mol­ecule is built up from fused five- and ten-membered rings with two additional ep­oxy ring systems and a meth­oxy­phenyl­piperazine group as a substituent. The ten-membered ring adopts an approximate chair–chair conformation, while the piperazine ring displays a chair conformation and the five-membered ring shows an envelope conformation with the C atom closest to the hy­droxy group forming the flap. The mol­ecular conformation is determined by an O—H⋯N hydrogen bond between the hy­droxy group and a piperazine N atom. The crystal structure is built up by weak C—H⋯O inter­actions

A theoretical investigation of the reactivity and regioselectivity of triterpene derivatives using difference local index, Parr functions.

A theoretical study of the reactivity and regioselectivity of thiosemicarbazide (TSC) condensation toward some carbonyl triterpenes was carried out using density functional theory with B3LYP/6-31G(d,p). The relative reactivity of these systems was rationalized by means of the global electrophilicity index. Positional selectivity, namely C3, C7 and C11, were evaluated using difference index Rk, Parr functions and difference of Parr function. The present study showed that the experimental results of the relative reactivity and regioselectivity of these reactions were correctly predicted using difference index Rk, Parr functions and difference of Parr function

(±)-N-[4-Acetyl-5-methyl-5-(4-methyl­cyclo­hex-3-en­yl)-4,5-dihydro-1,3,4-thia­diazol-2-yl]acetamide

The new title thiadiazole compound, C14H21N3O2S, was semi-synthesized starting from 1-(4-methyl­cyclo­hex-3-en­yl)ethanone, a natural product isolated from Cedrus atlantica essential oil. The stereochemistry has been confirmed by single-crystal X-ray diffraction. The thia­diazo­line ring is roughly planar, although it may be regarded as having a half-chair conformation. The cyclo­hexenyl ring has a half-chair conformation. The most inter­esting feature is the formation of a pseudo-ring formed by four mol­ecules associated through N—H⋯O hydrogen bonds around a fourfold inversion axis, forming an R 4 4(28) motif