COHERENCE DISCOURSE STRATEGY OF PASAMBAHAN:MINANGKABAU CULTURAL DISCOURSE

Pasambahan is one of well-known spoken discourse in Minangkabau. It is a medium for demonstrating speaking skills between the spokesperson of the host and the guests in several traditional events in Minangkabau. This research seems important to reveal the existence of symptoms of cohesion and semantic coherence in pasambahan discourse in Minangkabau ceremonies. Therefore, this present research aimed to find out the cohesive devices of the coherence relationship and the ways to achieve coherence in pasambahan. These two problems will be examined in terms of discourse analysis. Halliday and Hasan (1979) and Oshima and Hogue (2006) are reviewed to identify their claims about cohesion and coherence and apply them in pasambahan. The document review technique, which is one of the qualitative research methods, is employed in the study. The data in the form text of pasambahan were taken from written source, that is, pasambahan makan minum ‘Pasambahan done before starting the banquet’ taken from Minangkabau Panitahan Adat Alur book by Jamilus Jamin (2006). The results show that as a discourse, pasambahan shows symptoms of cohesion and coherence. The text coherence is achieved in several ways, namely (1) reiteration of key words, (2) the use of consistent pronoun, (3) the use of conjunction, and (4) arranging ideas in chronological order Ways 1 to 3 show a big role of cohesive devices in achieving text coherence, that is, the pattern of coherence that emerges is the coherence marked by linguistics units. Hence, it is an explicit relationship. Some marke rs found are repetition, synonymy, antonymy, pronoun, and conjunction. The coherence relationship can occur between words, phrases, clauses, and sentences. However, the way 4 shows the symptoms of coherence achieved without lingual markers (implicit), meaning that coherence is achieved through semantic relationships between sentences forming the text.

Author Identity and the Struggled for Power in Seratus Hari Keliling Indonesia, Kompas TV

This study is a discourse-based work which analyses the author identity construction in the novel Seratus Hari Keliling Indonesia (Seratus HKI) Kompas TV in order to reveal the authors’ struggle for power. The data of this study is obtained from f the vocabulary found in the Seratus HKI Kompas TV. Using the theory of Critical Discourse Analysis (CDA), this study applies the framework model of Norman Fairclough critical discourse analysis with the focus on the textual level. The finding shows that the identity (self-identification) of the author as a part of the government, local community, and foreigners are very much influenced by the interest of the nation, Indonesian citizens, conservation, environment, humanistic values, nationalism and patriotism. The analysis on the vocabulary found in HKI is emphasized on : (1) the vocabulary as a key words, (2) the usage of pronouns, and (3) rhetorical language’s style. Self-identification on Seratus HKI Kompas TV is relevant with the slogan of Kompas TV inspiring Indonesia by enlighting people and as a documentary journey that insert the national ideology.

Pyrolysis of 2-methoxy-5,5-dimethyl-2-methylthio- 2,5-dihydro[1,3,4]oxadiazole studied with photoelectron spectroscopy and DFT calculations — He(I) photoelectron spectrum of methoxy(methylthio)carbene

Gas-phase pyrolysis of 2-methoxy-2-methylsulfanyl-5,5-dimethyl-2,5-dihydro[1,3,4]oxadiazole (1) (also known as 2-methoxy-5,5-dimethyl-2-methylthio-2,5-dihydro[1,3,4]oxadiazole and 2-methoxy-2-methylthio-5,5-dimethyl-Δ3-l,3,4-oxadiazoline) in the source of an UV photoelectron spectrometer, by means of a CW CO2 laser as directed heat source, gave a photoelectron (PE) spectrum that included ionization bands belonging to acetone and methoxy(methylthio)carbene (3). Photoelectron spectra of authentic samples of (E)-1,2-dimethoxy-1,2-dimethyl thioethene (4), (Z)-1,2-dimethoxy-1,2-dimethylthioethene (5), S-methyl thioethanoate (6), and O-methyl ethanethioate (7), which can be derived by dimerization and rearrangement of the carbene, established that these compounds are not present in the pyrolysate. DFT calculations at the B3PW91/6-31+G(d,p) level and simulation of PE spectra at the B3LYP/6-31+G(d,p) level were instrumental in the interpretation of the experimental results. From the available experimental and calculated data, 3 is formed in a Sickle conformation upon pyrolysis of 1. Transition states for the rearrangement of 3 were examined with QTAIM. Key words: 2-methoxy-5,5-dimethyl-2-methylthio-2,5-dihydro[1,3,4]oxadiazole, pyrolysis, He(I) photoelectron spectroscopy, methoxy(methylthio)carbene, DFT calculations, QTAIM.

New investigation of the reaction of 2-amino-2-oxazolines with isocyanates and isothiocyanates. Evidence of a transposition during the second step

The reaction of some 2-amino-2-oxazolines with isocyanates and arylisothiocyanates yields 3-monosubstituted or 2,3-disubstituted 2-iminooxazolidines depending on the experimental conditions and on the nature of the electrophile reactants. The structures of a mono- and a disubstituted derivative were established by X-ray analysis. The chemical behaviour of the compounds was investigated by molecular and quantum mechanics calculations. An intramolecular transposition during the second step of the reaction was found. Key words: 2-amino-2-oxazolines, iso(thio)cyanates, transposition. X-ray structure, MOPAC calculations.

2-Azabuta-1,3-diene-4-carbonitriles: stereoselective synthesis and nucleophilic substitution at the carbon–nitrogen double bond

The synthesis of (E)-1-methoxy-2-azabuta-1,3-diene-4-carbonitriles was performed by methylation of N-alkenylamides 9 and 11. The Z isomers were obtained by treatment of (E)-1-methylthio-2-azabuta-1,3-diene-4,4-dicarbonitriles with sodium methoxide in methanol. We also describe the reactions of (E)-1-methylthio-2-azabuta-1,3-diene-4,4-dicarbonitriles with pyrrolidine, which afforded 1-(1-pyrrolidinyl) derivatives 20, 21, and 23. X-ray crystallographic analyses of 21 and 23 established the E stereochemistry of the C—N double bond. Key words: 2-azabuta-1,3-diene-4-carbonitriles: stereoselective synthesis, nucleophilic substitution and X-ray diffraction; N-alkenylamides: methylation.

Dihydroxyacids from the chlorination of ketones: an unexpected process

Chlorination of propiophenone in aqueous alkali at room temperature, with low concentrations of hypochlorite, leads to 2-phenylglyceric acid as the major product. This acid is formed by further oxidation of 1-phenyl-1,2-propanedione, which is an intermediate in the oxidation of propiophenone. Formation of this acid is reasonable in the light of other halogenation chemistry. Analogous reactions are observed for butyrophenone, which yields 2,3-dihydroxy-2-phenylbutanoic acid, and for cycloheptanone, which yields 1,2-dihydroxycyclohexanecarboxylic acid. Key words: 2-phenylglyceric acid, propiophenone, chlorination, hydrolysis, rearrangement, cycloheptanone, 1,2-dihydroxycyclohexanecarboxylic acid.

2-Phenyladamantane as a model for axial phenylcyclohexane. 1H NMR and molecular orbital studies of motion about the Csp2—Csp3 bond

The 1H NMR spectra of the aromatic groups of 2-phenylcyclohexane and 2-phenyladamantane, in CS2/C6D12 solution at 300 K, are analyzed to yield the long-range coupling constants between the α and ring protons. The coupling over six bonds is related to the internal rotational potential about the Csp2—Csp3 bond in these molecules. It is confirmed that the equatorial isomer of phenylcyclohexane has the parallel conformer, that in which the aromatic plane lies in the symmetry plane bisecting the cyclohexane moiety, as the most stable. The apparent twofold barrier to rotation about the exocyclic carbon–carbon bond follows as 7.1 kJ/mol from the six-bond coupling constant. For 2-phenyladamantane, the six-bond coupling constant strongly implies that the perpendicular conformer, perhaps slightly skewed, is that of lowest energy and that the apparent twofold barrier to rotation about the Csp2—Csp3 bond is about 7.5 kJ/mol. Insofar as 2-phenyladamantane mimics axial phenylcyclohexane, these results confirm recent conclusions about the conformation of the latter and provide evidence for its internal mobility. Geometry-optimized AMI and STO-3G MO computations are reported for the internal motion in both isomers of phenylcyclohexane. The former agree best with experiment for the equatorial isomer, but both imply a significant fourfold, of opposite sign to the twofold, component of the internal rotational potential. For the axial isomer, the two sets of computations find a skewed perpendicular conformer as most stable, in rough agreement with force-field results. However, the barrier to rotation about the Csp2—Csp3 bond is computed as small and AMI has the parallel conformer as more stable than the perpendicular. Key words: 2-phenyladamantane, 1H NMR and internal rotation; phenylcyclohexane, 1H NMR and internal rotation; MO computations, 2-phenyladamantane and phenylcyclohexane.

The conformational behaviour of 2-aryloxytetrahydropyrans and 2-acetoxytetrahydropyran, and barrier to ring inversion

The 13C nuclear magnetic resonance data of a series of 2-(4-substituted-phenoxy)tetrahydropyrans at 156 K and in CF2Br2 and CHFCl2 solvents show that the axial preference increases with electron withdrawal in the aryloxy group: from 79% (ΔG°E→A = −0.4 kcal mol−1) (4-OCH3) to 90% (ΔG°E→A = −0.7 kcal mol−1) (4-NO2) in CF2Br2. The axial preference (anomeric effect) is smaller in the more polar CHFCl2 solvent, as expected, and the substituent effect is smaller also: change in ΔG°E→A from −0.3 (4-OCH3) to −0.5 (4-NO2) kcal mol−1. However, the axial preference of 2-acetoxytetrahydropyran is shown to be smaller than that of 2-phenoxytetrahydropyran in CF2Br2 solvent although the acetoxy group is expected to be more electronegative than the phenoxy group. Furthermore, the polarity of the solvent has no effect on the conformational equilibrium of 2-acetoxytetrahydropyran. The results are interpreted in terms of both orbital and electrostatic interactions. The ring-inversion barrier of 2-alkoxy and 2-aryloxytetrahydropyrans, determined by the temperature-coalescence method, is lower than that of tetrahydropyran by about 1.5 kcal mol−1. Key words: 2-substituted tetrahydropyrans, conformational analysis, anomeric effect, ring inversion.

In vitro Antimicrobial Activity of Some Synthetic Isoindolinone and Isoquinolinone Derivatives

A total of six N-substituted benzamides, eight isoindolinone derivatives and six isoquinolinone analogs have been screened against five Gram positive and twelve Gram negative bacteria as well as four human fungal pathogens. From the antimicrobial screening, it is evident that 2-iodo-N-subustituted tetrahydro-1-oxo isoquinoline-3-carboxylic acids showed very prominent activity at a concentration 200 µg/disc, while the N-subtituted-3-alkyl isoindolin-1-one acetates showed weak to moderate activity. At the same time, 2-iodo-N-subustituted benzamides revealed very poor activity. Key words: 2-iodo-N-substituted benzamide, Isoindolinone, Isoquinolinone, Antimicrobial assay, Disc diffusion. Dhaka Univ. J. Pharm. Sci. Vol.5(1-2) 2006 The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website