Enantiospecific first total synthesis of cucumin-H

Enantiospecific first total synthesis of the linear triquinane sesquiterpene cucumin-H has been described. (R)-Limonene has been employed as the chiral starting material and a combination of Claisen rearrangement, intramolecular cyclopropanation and Nazarov reactions are employed for the regio- and stereospecific construction of the triquinane framework.

Zero momentum gluons and the total pp and pbarp cross-sections

We describe a QCD motivated model for total cross-sections which uses the eikonal representation and incorporates QCD mini-jets to drive the rise with energy of the cross-section, while the impact parameter distribution is obtained through the Fourier transform of the transverse momentum distribution of soft gluons emitted in the parton-parton interactions giving rise to mini-jets in the final state. A singular but integral expression for the running coupling constant in the infrared region is part of this model.

QCD and total cross-sections: photons and hadrons

In this contribution, we discuss a total cross-section model which can be applied to both photon and purely hadronic processes. We find that the model can reproduce photo-production cross-sections, as well as extrapolations of gamma p processes to gamma p using vector meson dominance models, with minimal modifications from the proton case.

Total Factor Productivity Growth and Output Growth in Indian Electronics Industry in the Liberalization Era: An Empirical Examination

This paper analyses the efficiency and productivity growth of Electronics industry, which is considered one of the vibrant and rapidly growing manufacturing industry sub-sectors of India in the liberalization era since 1991. The main objective of the paper is to examine the extent and growth of Total Factor Productivity (TFP) and its components namely, Technical Efficiency Change (TEC) and Technological Progress (TP) and its contribution to total output growth. In this study, the electronics industry is broadly classified into communication equipments, computer hardware, consumer electronics and other electronics, with the purpose of performing a comparative analysis of productivity growth for each of these sub-sectors for the time period 1993-2004. The paper found that the sub-sectors have improved in terms of economies of scale and contribution of capital.The change in technical efficiency and technological progress moved in reverse directions. Three of the four industry witnessed growth in the output primarily due to TFPG and the contribution of input growth to output growth had been negative/negligible, except for Computer hardware where contribution from both input growth and TFPG to output growth were prominent. The paper explored the possible reasons that addressed the issue of low technical efficiency and technological progress in the industry.

Total synthesis of panaxytriol and panaxydiol

The enantioselective total synthesis of the diyne containing natural products panaxytriol and (3S,10R)-panaxydiol from L-tartaric acid is reported. Key steps in the synthesis include the elaboration of a gamma-hydroxy amide derived from tartaric acid to the required alkyne and the formation of the desired diyne unit by a Cadiot-Chodkiewicz coupling. (C) 2011 Elsevier Ltd. All rights reserved.

Total synthesis of (-)-ent-pachastrissamine (ent-Jaspine B)

The total synthesis of the enantiomer of the tetrahydrofuran containing natural product Jaspine B is reported. The key reactions in the synthesis include formation of the tetrahydrofuran unit by an acid mediated Williamson etherification and a subsequent elaboration with an olefin cross metathesis reaction. (C) 2011 Elsevier Ltd. All rights reserved.

Total Factor Productivity in Indian Electronic Sector after Liberalisation: Sources and Outcomes

This paper analyses the efficiency and productivity growth of the Electronic Sector of India in the liberalization era since 1991. The study gives an insight into the process of the growth of one of the most upcoming sector of this decade. This sector has experienced a vast structural change along with the changing economic structures in India after liberalisation. With the opening up of this sector to foreign market and incoming of multinational companies, the environment has become highly competitive. The law that operates is that of Darwin’s ‘Survival of the fittest’. Existing industries experience a continuous threat of exit due to entrance of new potential entrants. Thus, it becomes inevitable for the existing industries in this sector to improve productivity growth for their survival. It is thus important to analyze how the industries in this sector have performed over the years and what are the factors that have contributed to the overall output growth.

Total and inelastic cross sections at LHC at root s=7 TeV and beyond

We discuss expectations for the total and inelastic cross sections at LHC CM energies root s = 7 TeV and 14 TeV obtained in an eikonal minijet model augmented by soft gluon k(t)-resummation, which we describe in some detail. We present a band of predictions which encompass recent LHC data and suggest that the inelastic cross section described by two-channel eikonal models include only uncorrelated processes. We show that this interpretation of the model is supported by the LHC data.

An Enantiospecific Formal Total Synthesis of the 5-8-5 Tricyclic Diterpene ent-Fusicoauritone

An enantiospecific formal total synthesis of the 5-8-5 tricyclic diterpene fusicoauritone has been accomplished, starting from 5-isopropyl-2-methylcyclopent-1-enemethanol [available in three steps from (R)-dihydrolimonene] employing two ring-closing-metathesis reactions for the construction of the eight- and five-membered rings.

Enantiospecific first total synthesis of (6S,7R)-silphiperfolan-6-ol

Enantiospecific first total synthesis of the angular triquinane sesquiterpene (65,7R)-silphiperfolan-6-ol has been accomplished, starting from 2-(3-isopropenyl-2-methylene-1-methylcyclopent-1-yl)acetic acid (readily available from (R)-limonene) employing an efficient, regioselective intramolecular rhodium carbenoid insertion into the CH bond of a tertiary methyl group as the key step. (C) 2012 Elsevier Ltd. All rights reserved.

Enantiospecific total synthesis of 15-hydroxy-5-(methoxymethoxy)crinipellin-9-one

Enantiospecific total synthesis of the crinipellin mentioned in the title was accomplished. In the present synthesis cyclopentane ring in campholenaldehyde was identified as the B-ring, two intramolecular rhodium carbenoid CH insertion reactions were employed for the construction of the A and C rings, and an intramolecular Michael addition reaction was utilized for the construction of the D-ring of crinipellin. (C) 2012 Elsevier Ltd. All rights reserved.