Total Synthesis of (R)-(−)-β-Cuparenone

Abstract

(R)-(?)-β-Cuparenone has been synthesized from (S)-(+)-acid-2 obtained via resolution of the racemic acid. Two of the noteworthy steps are (a) repeated methylation of ester (+)-8 with LDA/MeI to furnish (+)-10 and (b) the reaction of 12, having two neopentyl units with NaCN.     

Synthesis of Herbicides Using Polymer Supported 2, 4-Dichlorophenoxy Acetic Acid Anion

2, 4-Dichlorophenoxy acetic acid anion supported on anion exchange resin (Tulsion A-27 Chloride form) was treated with appropriate dihalide in acetonitrile at 25°C or 80 – 85°C to give corresponding diesters of 2, 4-dichlorophenoxy acetic acid as effective herbicides.

     

A convenient synthesis of enantiomerically pure (R)-mexiletine using hydrolytic kinetic resolution method

Enantiopure (R)-mexiletine was prepared in a simple and practical way using hydrolytic kinetic resolution method of terminal epoxide by Jacobsen’s catalyst. High enantiomeric purity (98% ee) was achieved and the method is well amenable to industrial scale-up.     

Computing Minimal Forecast Horizons:An Integer Programming Approach

In this paper, we use integer programming (IP) to compute minimal forecast horizons for the classical dynamic lot-sizing problem (DLS). As a solution approach for computing forecast horizons, integer programming has been largely ignored by the research community. It is our belief that the modelling and structural advantages of the IP approach coupled with the recent significant developments in computational integer programming make for a strong case for its use in practice. We formulate some well-known sufficient conditions, and necessary and sufficient conditions (characterizations) for forecast horizons as feasibility/optimality questions in 0–1 mixed integer programs. An extensive computational study establishes the effectiveness of the proposed approach.     

Bianchi Type-III Cosmological Model with Negative Constant Deceleration Parameter in Brans Dicke Theory of Gravitation

Bianchi type-III space time is considered in the presence of perfect fluid source in the scalar-tensor theory of gravitation proposed by Brans and Dicke (Phys. Rev. 124:925, 1961). With the help of special law of variation for Hubble’s parameter proposed by Bermann (Nuovo Cimento 74B:182, 1983) a cosmological model with negative constant deceleration parameter is obtained in the presence of perfect fluid with disordered radiation. Some physical and kinematical properties of the model are also discussed.     

A facile enantioselective synthesis of enantiomerically pure (R)-phenoxybenzamine hydrochloride using the hydrolytic kinetic resolution method

A practical and highly efficient enantioselective synthesis of (R)-phenoxybenzamine hydrochloride has been described for the first time using Jacobsen’s hydrolytic kinetic resolution of a terminal epoxide as a key step and source of chirality.     

Bianchi Type-III String Cosmological Models

Bianchi type III space time is considered in the presence of cosmic strings in Einstein’s general theory of relativity. Exact cosmological models are presented with the help of relation C=B ⁿ between metric coefficients C and B. Some physical properties of the model in each cases are discussed.     

Potential anticonvulsants. VII. Synthesis of 5′-methylspiro[3H-indole-3,2′-thiazolidine]-2,4′(1H)-diones

The title compounds have been prepared, by the cyclocondensation of thiolactic acid with isatin-3-imines. 5′-Methyl-3′-phenyl-spiro[3H-indole-3,2′-thiazolidine]-2,4′(1H)-dione has been subjected to the Mannich condensation to give 1-substituted derivatives. With one exception, all of the products were inactive in an anticonvulsant screen.     

Solid-phase synthesis of tertiary-amino linked benzamides: a versatile method for forming C-N bonds with electron-rich and electron-poor anilines

There currently are a wide variety of methods for forming C-N bonds on solid support. Two preferred methods are reductive aminations with resin bound amines or aldehydes as well as standard alkylation strategies. We herein disclose the scope and application of the Mitsunobu reaction of 2,4-dinitro-N-phenylbenzenesulfonamides derived from both electron-rich and electron-poor anilines as a practical and versatile addition to the repertoire of solid phase C-N bond forming reactions.     

Evaluation of co-polyaniline nanocomposite thin films as humidity sensor

Spin coated films of Co-Polyaniline nanocomposite are evaluated for their transmission properties using He-Ne laser for humidity sensing. The thickness (17-29 microm) of the films is varied by multiple deposition of Co-Polyaniline nanocomposite on a glass substrate. The samples exhibit typically two to three regions in their sensitivity curve when tested in the relative humidity (RH) range of 20-95%. The sensitivity ranges from 0.1 mV/%RH to 12.26 mV/%RH for lower to higher thickness. The sensors show quick response of 8s (20-95%RH), and a recovery time of 1 min (95-20%RH) with good repeatability, reproducibility and low hysteresis effect. The sensitivity of the sensor increases with humidity and thickness. Material characterization is done by X-ray diffraction (XRD), scanning electron micrograph (SEM) and Fourier transform infra-red spectroscopy (FTIR).