Simultaneous Syntheses Research Articles

Photoinduced molecular transformations. Part 135. New synthesis of taiwanin C and justicidin E based on a radical cascade process involving β-scission of alkoxyl radicals generated from 3- and 8-aryl-1-ethyl-1,2-dihydrocyclobuta[b]naphthalen-1-ols prepared by thermolysis of (Z)-tert-butyl 3-amino-3-(bicyclo[4.2.0]octa-1,3,5-trien-7-yl)propenoates

A new general synthesis of naturally occurring phthalide lignans, based on a radical cascade process triggered by a regioselective β-scission of the alkoxyl radicals generated by photolysis of the hypoiodites of 8-aryl-1-ethyl-1,2-dihydrocyclobuta[b]naphthalen-1-ols, is described. Two phases are involved in the present synthesis of phthalide lignans; the first is a new general synthesis of tert-butyl 4-aryl-3- and 4-aryl-8-aminonaphthalene-2-carboxylates by an electrocyclic reaction of o-quinonedimethides thermally generated from (Z)-tert-butyl 3-amino-3-(bicyclo[4.2.0]octa-1,3,5-trien-7-yl)propenoates; the second is a transformation of the protected 4-aryl-3-aminonaphthalene-2-carboxylic acids into the phthalide lignans. This latter phase involves their successive conversions into 3- and 8-arylcyclobuta[b]naphthalen-1 (2H)-ones via the formation of a benzyne intermediate, and then into 3- and 8-aryl-1-ethyl-1,2-dihydrocyclobuta[b]naphthalen-1-ols, followed by β-scission of the alkoxyl radicals generated by photolysis of their hypoiodites, generated in situ with the mercury(II) oxide–iodine reagent in benzene. Simultaneous syntheses of the naturally occurring phthalide lignans taiwanin C and justicidin E were thus achieved.

Fully automatic simultaneous multiple peptide synthesis in micromolar scale - rapid synthesis of series of peptides for screening in biological assays.

A new method of simultaneous multiple peptide syntheses on polystyrene support in the wells of microtiterplates is illustrated by the syntheses of 31 overlapping segments of endothelin. All reagent and solvent handling is automatically performed by a freely programmable robotic sample processor.

Mechanistic studies on the phosphoramidite coupling reaction in oligonucleotide synthesis. I. Evidence for nucleophilic catalysis by tetrazole and rate variations with the phosphorus substituents.

Tetrazole catalyzed reactions of a series of phosphoramidites, 5'-O-DMTdT-3'-O-P(OR1)NR2(2) (1a-h), with 3'-O-SiButPh2-6-N-benzoyl-dA (2a) in acetonitrile solution have been studied. It is found that the coupling rate depends very much on whether tetrazole is added before or after 2a, and that dialkylammonium tetrazolide salts are inhibitors. These and other facts are evidence that the reactions are subjected to nucleophilic catalysis by tetrazole, in addition to acid catalysis. The rate variations with phosphorus substituents of 1a-h are NEt2 greater than NPri2 greater than N(CH2CH2)O greater than NMePh, and OMe greater than OCH2CH2CN greater than OCHMeCH2CN greater than OCMe2CH2CN much greater than OC6H4Cl. The inhibitor properties of dialkylammonium tetrazolides have practical consequences for the efficiency of DNA syntheses, when in situ prepared phosphoramidites are used; the same would apply for segmented, simultaneous syntheses or syntheses where recycling is performed.

Cognitive processing, language awareness, and reading in Grade 2 and Grade 4 children

The role of cognitive processing and language awareness in relation to reading is discussed. The framework for cognitive processing was Luria's (1966a, Higher cortical functions in man, New York: Basic Books; 1966b, Human brain and psychological processes, New York: Harper & Row) simultaneous and successive syntheses. Language awareness involved understanding of phonological representation, ambiguities, and incongruities. The sample of 56 Grade 2 and 64 Grade 4 children was administered a battery of seven “simultaneous-successive” tasks. Principal component and promax oblique factor analyses and factor scores were used to classify the children as low-low, low-high, high-low, and high-high simultaneous-successive “processors.” A series of ANOVAs showed significant differences by grade and level of cognitive processing for the three language awareness tasks and for reading. These tasks and factor scores derived from the simultaneous and successive components of the within correlation matrix for the total sample of 120 children after removing covariance associated with the two grades were subjected to stepwise multiple regression analyses and a path analysis to tease out the contribution of these components to reading. Results showed a much greater direct effect from language awareness on reading than simultaneous and successive syntheses. Ability to reflect on language and to use language as “disembedded modes of thinking” are seen as central to reading acquisition and development.

A new general approach for the simultaneous chemical synthesis of large numbers of oligonucleotides: segmental solid supports

A new approach is described which will allow the simultaneous synthesis of large numbers of pre-defined oligonucleotide chains. No machine aid is needed. The simultaneous syntheses can be performed by one person and do not require much more time than is currently needed for the synthesis of just one oligonucleotide in existing strategies. The general idea is the following: One uses noninterchangeable polymeric entities from each of which enough OD units can be isolated after completion of the syntheses. Whenever growing chains on different entities have to be elongated with the same building block these entities are gathered in the same reaction vessel. After such a common reaction cycle the entities are separated and now combined according to the next common building blocks etc. The practicability of this approach is demonstrated by the synthesis of d(T-A-A-T-A-T-T-A) and d(T-A-G-T-A-C-T-A) on cellulose filter disks following the phosphotriester approach.

Simultaneous syntheses of cytoplasmic and chloroplastic ribosomal RNA during the cell cycle ofDunaliella

Chloroplastic and cytoplasmic ribosomal RNA syntheses were analyzed in synchromous culteres. All 4 rRNA species are simultaneously accumulated during the light period of the cell cycle. Cytoplasmic rRNA synthesis is repressed only during the later part of the S phase.

Cognitive processes and syntactical structure: Analyses of paradigmatic and syntagmatic associations

Research in two separate traditions in the study of language functions has suggested in a parallel fashion that paradigmatic and syntagmatic processes form an important distinction in the understanding of language learning and conceptual development. One tradition is developmental and experimental studies of word associations, and the other is research on aphasia, as exemplified particularly by the work of A.R. Luria. The relative contributions of these two areas are discussed, and two exploratory studies based on individual differences in simultaneous and successive syntheses are described. Suggestions are made for combining studies of individual differences with other approaches to extend the theoretical basis of paradigmatic and syntagmatic processes.

Coding, Planning and Mental Retardation: Theory, Evidence and Implications

The frontal lobes of the human brain represent a functional unit for projecting all aspects of a person's thinking into the future. In contrast, the temporal and occipital-parietal brain divisions are concerned with the processing of information about present and past events. These differences in role distinguish the frontal lobes from the remaining posterior cortex, and in this view, brain functions are split latitudinally rather than hemispherically. This paper traces the development of an integrated model of cognition stemming from Soviet neuropsychology and reviews recent research on simultaneous and successive syntheses; some implications for mental retardation are given.

Simultaneous synthesis of pectin lyase and carotovoricin induced by mitomycin C, nalidixic acid or ultraviolet light irradiation in Erwinia carotovora.

When Erwinia carotovora Er, a bacteriocinogenic strain, was induced after irradiation by ultraviolet (UV) light or inhibitors of DNA synthesis, such as mitomycin C or nalidixic acid, pectin lyase and bacteriocin (designated carotovoricin) activity appeared in the culture fluid. The optimal dose of each of these agents for producing the enzyme or bacteriocin was identical, and the time courses for both were essentially the same. Therefore, we assumed that the synthesis of the enzyme and bacteriocin was regulated by the same mechanism, in which a repressor inactivated by UV light, mitomycin C or nalidixic acid was involved. The other three bacteriocinogenic strains of E. carotovora also formed pectin lyase, in addition to carotovoricin in the presence of mitomycin C, indicating that simultaneous syntheses of pectin lyase and carotovoricin were widespread phenomenon in bacteriocinogenic strains of E. carotovora.

Simultaneous and Successive Cognitive Processes in the Mueller-Lyer Illusion

Performance in the Mueller-Lyer Illusion was analyzed for whole and partial presentations of the figure. S s were 120 third grade boys and girls. Four experimental groups were formed with the use of the human abilities model of simultaneous and successive syntheses, and the two types of presentation were given to each group. Results indicated that illusory effects in both presentations of the figure were significantly reduced by ability in simultaneous synthesis. Performance in the two presentations was also affected by successive ability, but these effects were in opposite directions for the two forms of presentation. The results did not support Piaget's theory of perceptual development, although they were consistent with the theory of simultaneous and successive syntheses. Suggestions are made for the design of future research.

Simultaneous and successive syntheses and linguistic processes1

The present study investigated the relationships between simultaneous and successive modes of cognitive processing and performance on word association, ambiguities and class inclusion tasks in a sample of 60 grade three children. Simultaneous processing was significantly related to class inclusion performance and to comprehension of lexical ambiguities. There was also some evidence of a relationship between paradigmatic responding on the word association task and simultaneous processing. Successive processing was significantly related to surface structure and underlying structure ambiguities and was also involved in class inclusion performance. These results are consistent with hypotheses derived from the neurolinguistic theories of Luria and Jakobson.

Level I and Level II abilities: Some theoretical reinterpretations

Some of the major assumptions and premises of the theory of Level I and Level II abilities are examined using a recent model of cognitive abilities known as simultaneous and successive syntheses. It is found that the empirical evidence for Level I and Level II abilities can be interpreted parsimoniously using the simultaneous‐successive model. The result of these reinterpretations is both increased clarification of some previously vague aspects of the Level I‐Level II theory, and greater understanding of the relationship of the theory to some current themes in cognitive psychology.

Preparation and Properties of tert‐Butyloxycarbonylaminoacyl‐4‐(oxymethyl) phenylacetamidomethyl‐(Kel F‐g‐styrene) Resin, an Insoluble, Noncrosslinked Support for Solid Phase Peptide Synthesis

AbstractThe Boc‐aminoacyl‐OCH2‐Pam‐ derivative of Kel F‐g‐styrene resin has been synthesized by a chemically unambiguous route. Direct amidoalkylation of the unsubstituted resin followed by hydrazinolysis gave the aminomethyl‐resin. The loaded resin was obtained by reaction with a Boc‐aminoacyl‐OCH2‐phenylacetic acid and DCC. The stability of this resin derivative towards acidolysis in trifluoroacetic acid was determined. Only 0.01–0.02 mol% loss of chains will occur in a single deprotection cycle in solid phase peptide synthesis. The peptidyl‐ and aminoacyl‐OCH2‐Pam‐(Kel F‐g‐styrene) resins were cleaved with anhydrous HF‐anisole at 0°C in near‐quantitative yield. Simultaneous syntheses of the model peptide Leu‐Ala‐Gly‐Val on this resin and on Val‐OCH2‐Pam‐poly(styrene‐co‐1% divinylbenzene) resin gave the same low levels of byproducts. No (<0.1%) intersite aminolysis was observed on treatment of Leu‐Ala‐Gly‐Val‐OCH<2‐Pam‐(Kel F‐g‐styrene) resin with 5% diisopropylethylamine in dichloromethane for 22 h.

Simultaneous and successive syntheses and intelligence

Recent studies on information processing have developed an alternative model of mental abilities which constitutes an integration of Russian clinical research and North American factor analytic research. This model proposes that information may be processed in a simultaneous synthesis or a successive synthesis. The present study examines variations in these syntheses in three intelligence groups in order to identify the types of information processing characteristic of different intelligence groups. A stratified sampling of verbal and nonverbal IQ was used to select 60 boys of age 9–10 in each of three verbal IQ ranges: 71–90, 91–110, and 111–130. A battery of tests used in previous research was administered to all subjects. Multivariate analyses of variance and discriminant analyses indicated that the IQ groups differed markedly on tests used to identify simultaneous synthesis, most notably Raven's Progressive Matrices, and differed slightly less on tests of successive synthesis. Factor analyses of the test intercorrelations for each group revealed more factorial invariance across the IQ groups than had been suggested by a previous exploratory study. It was concluded that strong individual differences exist in simultaneous and successive syntheses over the major portion of the standardized intelligence range, and no high degree of specialization of information processing was characteristic of an intelligence group.

Simultaneous and successive synthesis: An alternative model for cognitive abilities.

Current theories of the structure of cognitive abilities are critically examined and found to lack adequate description of the processes underlying the abilities. An alternative model, Luria's theory of simultaneous and successive syntheses, is presented and discussed. This model of information processing is supported by a number of factor analytic studies of cognitive abilities and then related to data from studies of memory, imagery, and language. Finally, a model of abilities in terms of a structure-process distinction is proposed. Ever since intelligence tests were devised, the concept of ability has been advanced as something underlying behavior. Often interchangeable with capacity, intellectual ability has been described as a general factor akin to mental energy (Spearman, 1927), the complexity and flexibility of a person's schemata (Vernon, 1960), a hierachy of reasoning and memory (Burt, 1972; Jensen, 1970), or the ability to meet new situations with old responses. Recently, there seems to be a shift from the postulation and study of abilities to an inquiry into processes (Messick, 1973). One of the apparent advantages of considering processes is their proximity to behavior or performance, describing modes of an individual's functioning in a test situation; it is easier and more meaningful to integrate the interplay between genetic endowments and the historical nature of an individual's experience with the characteristics of the task itself, as determinants of the processes used by an individual, rather than invoke the notion of abilities. Encouragement in viewing cognitive functions in terms of processes also comes from those who oppose faculty psychology. As based on factor analytic work, abilities often emerge as mental faculties, permanent and immutable, and dissociated from behavior. Humphreys (1962a, 1962b), for instance, reacts unfavorably to such a view by listing

Simultaneous Syntheses of Aromatic Carboxylic Acis and Phenols. V.

Simultaneous Syntheses of Aromatic Carboxylic Acis and Phenols. V.

Simultaneous Syntheses of Aromatic Carboxylic Acid and Phenols. II

Synthesis of p-methylbenzophenone involring the reaction of phosgene with a mixture of toluene and benzene in the presence of aluminum chloride cat alyst has been investgated. By the addition of 1 mole of toluene to a mixture of 6 moles of benzene, 8 moles of phosgene and 1.1 moles of aluminum chloride during 4 hrs at 0°c. and further stirring for 44 hrs, product composed of 53.6% p-methylbenzophenone (1), 14.5% p, p'-dimethylbenzophenone (2), 5.5% benzophenone (3), and 12.7% p-toluic acid was given. As a result of the othe procedure in which 1.2 moles of phosgene was introduced into a mixture of 6 moles of benzene, 1 mole of toluene and 1.1 moles of aluminum chloride at 50°c. for 6hr 50.0% (1), 10.0% (2) and 20.0% (3), were obtained respectively.

Simultaneous Syntheses of Aromatic Carboxylic Acids and Phenols. III

Formation of p-carboxybenzophenone by oxidation of p-methylbenzophenone with air in the presence of metal salt of organic acid has been investigated. Oxidation was carried out by blowing the air into the mixtuse of raw material and catalyst through the glass filter attached to the reaction tube of U-form under heating An example for suitable reaction condition is following; p-carboxybenzophenone is given in the yield of 47% by heating 100 parts of p-methylbenzophenone with 0.12 part of manganese naphth enate catalyst for 12 hrs at 210°c. under blow of air. Although the tests on addition of benzoyl peroxide or monochloroacetic acid as solvent has been done the yield was lower in each case.

Simultaneous Syntheses of Aromatic Carboxylic Acids and Phenols. I

Oxidation of p-carboxybenzophenone (1) with peracetic acid in glacial acetic acid or acetic anhydride as a solvent gave a monophenyl acid terephalate (2) and it was discovered that simultaneous syntheses of terephthalic acid and phenol were possible from hydrolysis of (2). The kinds of peracids and solvents used for the oxidation, the amount and time of pouring of hydrogen peroxide, the concentration of sulfuric acid, and the temp. of reaction have been investigated and the best condition for the reaction was proceeded as follows : To 1 mole (1), 13.3 moles of glacial acetic acid and 500 cc conc sulfuric acid, as a catalyst are added, and then the solution at 40°c is treated dropwise with 1.03 moles of 30% hydrogen peroxide in 30 min, stirred for 6 hr at this temp. The product (2) is hydrolyzed as usual with aqueous sodium hydroxide solution and the separation of the products by suitable means yields 86.5% of terephthalic acid with purity 97.6% (Hasen no. 65) and 83, 8% of phenol

Simultaneous Syntheses of Aromatic Carboxylic Acids and Phenols, IV

Oxidation of p-carboxybenzophenone (1) with peracetic acid in glacial acetic acid or acetic anhydride as a solvent gave a monophenyl acid terephalate (2) and it was discovered that simultaneous syntheses of terephthalic acid and phenol were possible from hydrolysis of (2). The kinds of peracids and solvents used for the oxidation, the amount and time of pouring of hydrogen peroxide, the concentration of sulfuric acid, and the temp. of reaction have been investigated and the best condition for the reaction was proceeded as follows : To 1 mole (1), 13.3 moles of glacial acetic acid and 500 cc conc sulfuric acid, as a catalyst are added, and then the solution at 40°c is treated dropwise with 1.03 moles of 30% hydrogen peroxide in 30 min, stirred for 6 hr at this temp. The product (2) is hydrolyzed as usual with aqueous sodium hydroxide solution and the separation of the products by suitable means yields 86.5% of terephthalic acid with purity 97.6% (Hasen no. 65) and 83, 8% of phenol