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PubMed2000

Activin maintains the condensed type of mitochondria in germ cells.

Development of germ cells during spermatogenesis is characterized by a complex series of differentiation events finally leading to the production of spermatozoa. Beside the main hormonal regulators, paracrine interactions are thought to play a major role in this process. Mitochondria in germ cells pass through unique alterations ranging from the 'typical' cristae-rich mitochondria found in spermatogonia to the 'condensed' form in pachytene spermatocytes. This study provides further support that paracrine factors produced by Sertoli cells, most likely activin A, are involved in germ cell differentiation as monitored by the maintenance of the physiological 'condensed' mitochondrial phenotype in primary spermatocytes. Culture of primary spermatocytes in Sertoli cell conditioned medium (SCCM) for 18 h resulted in the maintenance of a high percentage of 'condensed-type' mitochondria in comparison to cells cultured in Dulbecco's minimum essential medium (DMEM). Activin A, a product of Sertoli cells, showed at subnanogram concentrations a similar ability to SCCM to maintain a high percentage of spermatocyte mitochondria in the 'condensed' state, while inhibin had no effect. The addition of an antiserum specific for activin A resulted in a neutralization of the effect caused by activin A or SCCM. This strongly suggested that the active substance in SCCM was activin A. Taken together these data indicate that activin A is the first Sertoli cell product that has been identified to influence differentiation of male meiotic germ cells.

Activins↗

PubMed1977

Mutagenicities of smoke condensates and the charred surface of fish and meat.

Smoke condensates obtained from broiling fish showed mutagenic activity for Salmonella typhimurium TA100 and TA98. Metabolic activation was required to induce mutagenic activity of smoke condensates of some species of fish. The smoke condensate obtained during charcoal broiling of beefsteak was far less mutagenic than that of fish, with or without metabolic activation. Extracts of the charred surface of broiled fish and meat also contained mutagenic substances. These extracts needed metabolic activation to exhibit mutagenicities on TA98. The mutagenic activity of the smoke condensate obtained from one sardine weighing 100 g was equivalent to that of 132 micrograms benzo(a)pyrene and that of the charred surface of the sardine was equivalent to 358 micrograms benzo(a)pyrene. One piece of beefsteak weighing 190 g, contained mutagenic activity equivalent to that of 855 micrograns benzo(a)pyrene.

Animals↗

PubMed1984

Investigation on the carcinogenicity of emission condensate from brown coal-fired residential furnaces applied to mouse skin.

Flue gas condensate emitted from brown coal-fired stoves was tested in 3 dosages applied chronically to the skin of female CFLP mice twice a week over a period of 104 weeks. To answer the question which portion of the total carcinogenicity results from benzo[a]pyrene (BaP), this compound was taken as reference substance. The probit and Weibull analysis of the results showed a linear dose-response relationship for both tumor incidences and tumor induction times. The amount of BaP in the emission condensate (0.593 mg/g condensate) contributes about 15% to the total carcinogenic effect of the brown coal flue gas condensate.

Air Pollutants↗

PubMed2000

Phenolic glycosides and condensed tannins in Salix sericea, S. eriocephala and their F1 hybrids: not all hybrids are created equal.

The performance of hybrids depends upon the inheritance and expression of resistance traits. Secondary chemicals are one such resistance trait. In this study, we measured the concentrations of phenolic glycosides and condensed tannins in parental and F1 hybrid willows to examine the sources of chemical variation among hybrids. S. sericea produces phenolic glycosides, salicortin and 2'-cinnamoylsalicortin, and low concentrations of condensed tannin in its leaves. In contrast, S. eriocephala produces no phenolic glycosides but high concentrations of condensed tannins in its leaves. These traits are inherited quantitatively in hybrids. On average, F1 hybrids are intermediate for condensed tannins, suggesting predominantly additive inheritance or balanced ambidirectional dominance of this defensive chemical from the parental species. In contrast, the concentration of phenolic glycosides is lower than the parental midpoint, indicating directional dominance. However, there is extensive variation among F1 hybrids. The concentration of tannin and phenolic glycosides in F1 hybrid families is either (1) lower than the midpoint, (2) higher than the midpoint, or (3) indistinguishable from the midpoint of the two parental taxa. It appears that the production of the phenolic glycosides, especially 2'-cinnamoylsalicortin, is controlled by one or more recessive alleles. We also observed a two-fold or greater difference in concentration between some hybrid families. We discuss how chemical variation may effect the relative susceptibility of hybrid willows to herbivores.

Journal Article↗

PubMedDate not supplied

DNA topoisomerase IIalpha interacts with CAD nuclease and is involved in chromatin condensation during apoptotic execution.

Apoptotic execution is characterized by dramatic changes in nuclear structure accompanied by cleavage of nuclear proteins by caspases (reviewed in [1]). Cell-free extracts have proved useful for the identification and functional characterization of activities involved in apoptotic execution [2-4] and for the identification of proteins cleaved by caspases [5]. More recent studies have suggested that nuclear disassembly is driven largely by factors activated downstream of caspases [6]. One such factor, the caspase-activated DNase, CAD/CPAN/DFF40 [4,7,8] (CAD) can induce apoptotic chromatin condensation in isolated HeLa cell nuclei in the absence of other cytosolic factors [6,8]. As chromatin condensation occurs even when CAD activity is inhibited, however, CAD cannot be the sole morphogenetic factor triggered by caspases [6]. Here we show that DNA topoisomerase IIalpha (Topo IIalpha), which is essential for both condensation and segregation of daughter chromosomes in mitosis [9], also functions during apoptotic execution. Simultaneous inhibition of Topo IIalpha and caspases completely abolishes apoptotic chromatin condensation. In addition, we show that CAD binds to Topo IIalpha, and that their association enhances the decatenation activity of Topo IIalpha in vitro.

Animals↗

PubMed2005

[Exhaled breath condensate: standardized collection of samples from healthy volunteers].

Expired breath condensate collection is a noninvasive technique for obtaining a sample in which to analyze substances that reflect the functional status of the lung and other tissues. Twenty healthy volunteers provided 3 expired breath samples: the second was collected 20 minutes after the first and the third 48 hours after the first. The air and condensate volumes were assessed. The mean (SD) volume of condensate in exhaled air over a period of 15 minutes was 1.8 (0.5) mL (95% confidence interval [CI], 1.5-2 mL) and the coefficient of variation was 29%. Analysis of variance in the 3 samples demonstrated no significant differences. The mean volume of air inhaled over 15 minutes was 119 (25) L (95% CI, 112-125 L). These results indicate that it takes at least 15 minutes and the inhalation of some 120 L of air to collect a condensate volume that exceeds 1.5 mL, sufficient to allow distribution in aliquots to analyze fundamental physical and chemical properties (conductivity, pH) and certain relevant biomarkers.

Adult↗

PubMed2003

Dynamic changes of rDNA condensation state during mitosis in filamentous fungi revealed by fluorescence in situ hybridisation.

We visualised rDNA of two ascomycetes, Cochliobolus heterostrophus and Haematonectria haematococca, by fluorescence in situ hybridisation (FISH) and analysed the condensation state of rDNA during mitosis. Both fungi showed a similar course of change in rDNA condensation corresponding to different mitotic stages. rDNA was decondensed in its entire length at interphase, and became increasingly condensed during prophase. The condensation reached a maximum at metaphase, remaining in that state through anaphase. Metaphase observation revealed the single distal location on a chromosome of rDNA in each fungus. This study provides the first visual evidence of the cyclic change of the condensation/decondensation state of rDNA during mitosis in filamentous fungi by FISH.

Ascomycota↗

PubMed1991

Synergistic effect of histone H1 and nucleolin on chromatin condensation in mitosis: role of a phosphorylated heteromer.

Repeated motifs, rich in basic residues, are characteristic of both the N-terminal domain of the nucleolus-specific protein, nucleolin, and the second half of the C-terminal domain of histone H1. These repeats are also the target for phosphorylation by the mitosis-specific p34cdc2 kinase. We have previously shown that synthetic peptides [(KTPKKAKKP)2 for histone H1 and (ATPAKKAA)2 for nucleolin] corresponding to these two repeated motifs are able to act in synergy to induce DNA hypercondensation (Erard et al., 1990). In order to determine the molecular basis of this synergistic interaction, we have studied the condensation of the homopolymer poly(dA).poly(dT) in the presence of the two synthetic peptides. Circular dichroism has been used to monitor the psi (+)-type condensation and has revealed that phosphorylation enhances the synergistic effect of the two peptides. Analysis of different combinations of the two peptides suggests that there is a direct interaction between them which is stabilized by phosphorylation. Furthermore, there is a striking correlation between the degree of homopolymer condensation and the stability of the heteromeric complex. Phosphorylation takes place on the threonine residues on the repeat motifs within a region which is likely to adopt a beta-turn structure. Circular dichroism and infrared spectroscopy provide evidence that phosphorylation stabilizes the beta-turn structure of both peptides, and computer modeling shows that this may be due to steric hindrance imposed by the phosphate group. We suggest that phosphorylated nucleolin and histone H1 interact through their homologous domain structured in beta-spirals in order to condense certain forms of DNA during mitosis.

Amino Acid Sequence↗

PubMed2000

Vibriobactin biosynthesis in Vibrio cholerae: VibH is an amide synthase homologous to nonribosomal peptide synthetase condensation domains.

The Vibrio cholerae siderophore vibriobactin is biosynthesized from three molecules of 2,3-dihydroxybenzoate (DHB), two molecules of L-threonine, and one of norspermidine. Of the four genes positively implicated in vibriobactin biosynthesis, we have here expressed, purified, and assayed the products of three: vibE, vibB, and vibH. All three are homologous to nonribosomal peptide synthetase (NRPS) domains: VibE is a 2,3-dihydroxybenzoate-adenosyl monophosphate ligase, VibB is a bifunctional isochorismate lyase-aryl carrier protein (ArCP), and VibH is a novel amide synthase that represents a free-standing condensation (C) domain. VibE and VibB are homologous to EntE and EntB from Escherichia coli enterobactin synthetase; VibE activates DHB as the acyl adenylate and then transfers it to the free thiol of the phosphopantetheine arm of VibB's ArCP domain. VibH then condenses this DHB thioester (the donor) with the small molecule norspermidine (the acceptor), forming N(1)-(2, 3-dihydroxybenzoyl)norspermidine (DHB-NSPD) with a k(cat) of 600 min(-1) and a K(m) for acyl-VibB of 0.88 microM and for norspermidine of 1.5 mM. Exclusive monoacylation of a primary amine of norspermidine was observed. VibH also tolerates DHB-acylated EntB and 1,7-diaminoheptane, octylamine, and hexylamine as substrates, albeit at lowered catalytic efficiencies. DHB-NSPD possesses one of three acylations required for mature vibriobactin, and its formation confirms VibH's role in vibriobactin biosynthesis. VibH is a unique NRPS condensation domain that acts upon an upstream carrier-protein-bound donor and a downstream amine, turning over a soluble amide product, in contrast to an archetypal NRPS-embedded C domain that condenses two carrier protein thioesters.

Amide Synthases↗

PubMed1983

Condensed form of (dG-dC)n X (dG-dC)n as an intermediate between the B- and Z-type conformations induced by sodium acetate.

Circular dichroism and laser Raman spectroscopy reveal that the synthetic DNA polymer (dG-dC)n X (dG-dC)n undergoes a cooperative transition induced by sodium acetate from a right-handed B-form to a left-handed Z-type conformation with a midpoint at 2.05 M. However, at concentrations only slightly higher than the end point of this transition (above approximately 2.2 M) and up to approximately 2.65 M, the Z-form is not stable in solution but aggregates to form highly condensed DNA. A manyfold increase of positive ellipticity in the range 340-250 nm is observed which is indicative of a psi (+)-type structure. At even higher concentrations (greater than or equal to 2.7 M), the Z-form is stable without condensation, and there is no change in the inverted CD spectrum. All structural transitions are reversible except that it is not possible to redissolve the highly condensed psi (+)-form by further increasing the salt concentration to greater than or equal to 2.7 M. The very high cooperativity of these transitions enables the DNA polymer to adopt three distinctly different structures (B-, Z-, and psi-forms) within a narrow range of sodium acetate concentration (approximately 200 mM). The Raman spectra of the condensed form and the Z-form in very concentrated sodium acetate show that the psi (+)-type state forms without substantial changes of the secondary conformation of the DNA. This indicates that the left-handed Z-helix of (dG-dC)n X (dG-dC)n can form psi-type aggregates with an ordered superstructure similar to those observed for natural right-handed DNA helices.

Acetates↗

PubMedDate not supplied

Star-shaped poly(ethylene glycol)-block-polyethylenimine copolymers enhance DNA condensation of low molecular weight polyethylenimines.

Star-shaped poly(ethylene glycol)-block-polyethylenimine [star-(PEG-b-PEI)] significantly enhance plasmid DNA condensation of low molecular weight (MW) PEIs. The star-block copolymers were prepared via a facile synthesis route using hexamethylene diisocyanate as linker between PEG and PEI blocks. NMR and FT-IR spectroscopy confirmed the structures of intermediately activated PEG and final products. Furthermore, the copolymers were characterized by size exclusion chromatography, static light scattering, and viscosimetry. Their molecular weights (M(w) 19-26 kDa) were similar to high MW PEI (25 kDa). Thermoanalytical investigations (thermogravimetric analysis, differential scanning calorimetry) were also performed and verified successful copolymer synthesis. DNA condensation with the low MW PEIs (800 and 2000 Da) and their 4- and 8-star-block copolymers was studied using atomic force microscopy, dynamic light scattering, zeta-potential measurements, and ethidium bromide (EtBr) exclusion assay. It was found that low MW PEIs formed huge aggregates (500 nm to 2 microm) in which DNA is only loosely condensed. By contrast, the star-block copolymers yielded small (80-110 nm), spherical and compact complexes that were stable against aggregation even at high ionic strength and charge neutrality. Furthermore, as revealed in the EtBr exclusion assay these star-block copolymers exhibited a DNA condensation potential as high as high MW PEI. Since these star-(PEG-block-PEI) copolymers are composed of relatively nontoxic low MW PEI and biocompatible PEG, their potential as gene delivery agents merits further investigations.

Biocompatible Materials↗

PubMed2006

Phosphopeptide modification and enrichment by oxidation-reduction condensation.

Many cellular processes are regulated by the reversible phosphorylation of proteins. Despite the importance of monitoring protein phosphorylation, available methods to modify and enrich phosphopeptides from complex mixtures for subsequent mass spectrometric analysis are challenging. Here the oxidation-reduction condensation was shown for the first time to directly modify the phosphate of phosphopeptides and phosphoproteins. By coupling with a solid-phase resin, the oxidation-reduction condensation was validated for capture and recovery of phosphoserine-, phosphothreonine-, and phosphotyrosine-containing peptides from a peptide mixture. In addition, full-length phosphoproteins or phosphopeptides from a protein digestion were captured and recovered using the oxidation-reduction condensation, demonstrating its compatibility with protein mixtures. The strategy modifies all phosphopeptides, maintains high chemical selectivity, requires only two steps, and relies on commercially available reagents, suggesting that the oxidation-reduction condensation has the potential to enhance phosphopeptide enrichment methods and encourage development of efficient biochemical and proteomics tools targeting phosphorylation.

Amino Acid Sequence↗

PubMed2001

Protonation of platinated adenine nucleobases. Gas phase vs condensed phase picture.

Protonation of adenine carrying a Pt(II) moiety either at N7, N3, or N1 is possible in solution, but the site of protonation is influenced by the location of the Pt(II) electrophile and to some extent also by the overall charge of the metal entity (+2, +1, 0, -1), hence the other ligands (NH(3), Cl(-), OH(-)) bound to Pt(II). Quantum chemical calculations based on density functional theory (DFT) have been carried out for intrinsic protonation energies of adenine complexes carrying the following Pt(II) species at either of the three ring N atoms: [Pt(NH(3))(3)](2+) (1), trans- [Pt(NH(3))(2)Cl](+) (2a), cis-[Pt(NH(3))(2)Cl](+) (2b), trans-[Pt(NH(3))(2)Cl(2)] (3a), cis-[Pt(NH(3))Cl(2)] (3b), [PtCl(3)](-) (4), trans-[Pt(NH(3))(2)OH](+) (5a), cis-[Pt(NH(3))(2)(OH)](+) (5b), trans-[Pt(NH(3))(OH)(2)] (6a), cis-[Pt(NH(3))(OH)(2)] (6b), and [Pt(OH)(3)](-) (7). The data have been compared with results derived from solution studies (water) and X-ray crystallography, whenever available. The electrostatic effects associated with the charge of the metal entity have the major influence on the calculated intrinsic (gas phase) proton affinities, unlike the condensed phase data. Nevertheless, the relative gas phase trends correlate surprisingly well with condensed phase data; i.e., variation of the pK(a) values measured in solution is consistent with the calculated gas phase protonation energies. In addition to a systematic study of the ring proton affinities, proton transfer processes within the platinated adenine species were often observed when investigating Pt adducts with OH(-) ligands, and they are discussed in more detail. To the best of our knowledge, this is the first study attempting to find a systematic correlation between gas phase and condensed phase data on protonation of metalated nucleobases. The gas phase data provide a very useful complement to the condensed phase and X-ray experiments, showing that the gas phase studies are capable of valuable predictions and contribute to our understanding of the solvent and counterion effects on metal-assisted proton shift processes.

Adenine Nucleotides↗

PubMed1997

Characterization of the Self-Condensation Equilibrium of [Fe(4)S(4)(SH)(4)](2-): Spectroscopic Identification of a Unique Sulfido-Bridged Acyclic Tricubane Cluster.

Our interest in higher nuclearity sulfido-bridged Fe-S clusters, because of their occurrence in several proteins including nitrogenase, prompted us to investigate the solution chemistry of the functionalized cluster [Fe(4)S(4)(SH)(4)](2)(-) (1). (n-Pr(4)N)(2)[1] crystallizes in space group P2(1)/n of the monoclinic system with a = 26.201(1) Å, b = 11.4999(5) Å, c = 28.090(1) Å, and beta = 110.735(1) degrees. The X-ray structure reveals the conventional cubane-type geometry with an [Fe(4)S(4)](2+) core symmetry more closely approaching T(d)() than the tetragonally distorted D(2)(d)() symmetry reported for the (PPh(4))(2)[1] (Müller, A.; Schladerbeck, N. H.; Bögge, H. J. Chem. Soc., Chem. Commun. 1987, 35). In solution, 1 exists in dynamic equilibrium with self-condensation products formed through elimination of H(2)S and formation of sulfido-bridged cluster oligomers, one of which (4) is prevalent. The self-condensation equilibrium is shifted toward cluster 1. When acetonitrile solutions of 1 were treated with thiols more acidic than H(2)S, it was possible to detect hydrosulfido terminal ligand substitution products of 1 as well as those of the major self-condensation product 4. Detailed analysis of the products in acetonitrile solutions of 1, as well as those generated in solutions of 1 treated with acidic thiol, by electrospray mass spectrometry, and both (19)F and (1)H NMR spectroscopy indicates the presence of a sulfido-bridged acyclic trimer of [Fe(4)S(4)](2+) clusters, i.e. {[Fe(4)S(4)(SH)(3)](2)[Fe(4)S(4)(SH)(2)](&mgr;-S)(2)}(6)(-) (4), a hitherto unprecedented Fe-S structural pattern, as the principal Fe-S cluster self-condensation product.

Journal Article↗

PubMed2006

Understanding the native Californian diet: Identification of condensed and hydrolyzable tannins in tanoak acorns (Lithocarpus densiflorus).

The tanoak (Lithocarpus densiflorus) acorn was a staple food in the Native American diet and is still used in traditional dishes. Acorns from the genus Quercus have been shown to contain a large range of hydrolyzable tannins. However, neither hydrolyzable nor condensed tannins have been characterized in tanoak acorns. The aim of this study was to identify the full range of hydrolyzable and condensed tannins in extracts of tanoak acorns using liquid chromatography/electrospray ionization-mass spectrometry/mass spectrometry. Condensed tannins were identified as B type oligomers of (epi)-catechin (procyanidins) with a degree of polymerization up to six. Oligomers up to and including tetramers were identified by UV spectra and MS detection whereas pentamers and hexamers were detected only by MS. The total concentration of condensed tannins was 464 mg/100 g acorn pericarp. The concentration of propocyanidin monomers, dimers, trimers, and tetramers in acorn pericarp (mg/100 g acorn pericarp) were 95 +/- 10.9, 148 +/- 35.0, 90 +/- 17.9, and 131 +/- 1.9, respectively. No procyanidins were found in the acorn cotyledon tissue. A total of 22 hydrolyzable tannins were identified in methanolic extracts of acorn cotyledon tissue. Gallic acid derivatives predominated and included galloylated esters of glucose, hexahydrodiphenoyl esters of glucose, and methylated gallates. Galloylated esters of glucose were present as isomers of galloyl glucose, digalloyl glucose, and trigalloyl glucose. Mass spectral fragmentation patterns indicate the presence of one gallic acid-galloyl glucose isomer and two gallic acid-digalloyl-glucose isomers. No isomers of tetragalloyl glucose and pentagalloyl glucose were identified. Ellagic acid and ellagic acid pentoside were also identified.

California↗

PubMed2000

An efficient synthesis of cyclic IDP- and cyclic 8-bromo-IDP-carbocyclic-riboses using a modified Hata condensation method to form an intramolecular pyrophosphate linkage as a key step. An entry to a general method for the chemical synthesis of cyclic ADP-ribose analogues

An efficient synthesis of cyclic IDP-carbocyclic-ribose (3) and its 8-bromo derivative 6, as stable mimics of cyclic ADP-ribose, was achieved, and a condensation reaction with phenylthiophosphate-type substrate 15 or 16 to form an intramolecular pyrophosphate linkage was a key step. N-1-Carbocyclic-ribosylinosine derivative 28 and the corresponding 8-bromo congener 24 were prepared via condensation between N-1-(2,4-dinitrophenyl)inosine derivative 17 and a known optically active carbocyclic amine 18. Compounds 24 and 28 were then converted to the corresponding 5"-phosphoryl-5'-phenylthiophosphate derivatives 15 and 16, respectively, which were substrates for the condensation reaction to form an intramolecular pyrophosphate linkage. Treatment of 8-bromo substrate 15 with I2 or AgNO3 in the presence of molecular sieves 3A (MS 3A) in pyridine at room temperature gave the desired cyclic product 12 quantitatively, while the yield was quite low without MS. The similar reaction of 8-unsubstituted substrate 16 gave the corresponding cyclized product 32 in 81% yield. Acidic treatment of these cyclic pyrophosphates 12 and 32 readily gave the targets 6 and 3, respectively. This result suggests that the construction of N-1-substituted hypoxanthine nucleoside structures from N-1-(2,4-dinitrophenyl)inosine derivatives and the intramolecular condensation by activation of the phenylthiophosphate group with I2 or AgNO3/MS 3A combine to provide a very efficient route for the synthesis of analogues of cyclic ADP-ribose such as 3 and 6. Thus, this may be an entry to a general method for synthesizing biologically important cyclic nucleotides of this type.

Journal Article↗

PubMed2001

Zwitterion radicals and anion radicals from electron transfer and solvent condensation with the fingerprint developing agent ninhydrin.

Ninhydrin (the fingerprint developing agent) spontaneously dehydrates in liquid ammonia and in hexamethylphosphoramide (HMPA) to form indantrione, which has a sufficiently large solution electron affinity to extract an electron from the solvent (HMPA) to produce the indantrione anion radical. In liquid NH(3), the presence of trace amounts of amide ion causes the spontaneous formation of an anion radical condensation product, wherein the no. 2 carbon (originally a carbonyl carbon) becomes substituted with -NH(2) and -OH groups. In HMPA, the indantrione anion radical spontaneously forms condensation products with the HMPA to produce a variety of zwitterionic radicals, wherein the no. 2 carbon becomes directly attached to a nitrogen of the HMPA. The mechanisms for the formation of the zwitterionic paramagnetic condensation products are analogous to that observed in the reaction of ninhydrin with amino acids to yield Ruhemann's Purple, the contrast product in fingerprint development. The formation of anion and zwitterionic radical condensation products from ninhydrin and nitrogen-containing solvents may represent an example of a host of analogous polyketone-solvent reactions.

Journal Article↗

PubMed2006

Studies of the condensation of sulfones with ketones and aldehydes.

[reaction: see text] The condensation of ketones or aldehydes with sulfones was shown to give a variety of products. Condensation of 2-methylcyclohexanone with dimethyl sulfone using potassium t-butoxide as base gave useful yields of 1,2-dimethylenecyclohexane. Under the same conditions, cycloheptanone, 3-methyl-2-butanone, and 2-butanone were converted to dienes. Remarkably, these reaction conditions converted acetophenone into p-terphenyl (10%) and (E)-1,4-diphenyl-3-penten-1-one (44%). Propiophenone was converted to 2'-methyl-p-terphenyl (61%). Using alpha-tetralone produced 1-methynaphthalene and naphthalene. No reaction took place with beta-tetralone. Using diethyl sulfone with alpha-tetralone lead to pure naphthalene. Condensation of isobutyraldehyde and dimethyl sulfone using potassium t-butoxide gave isoprene in low yield. Using benzaldehyde and benzyl phenyl sulfone in N,N-dimethylacetamide gave 1,2-diphenyl-1-phenylsulfonylethylene, N,N-dimethylcinnamide, and a complex condensation product. Only 1,2-diphenyl-1-phenylsulfonylethylene was obtained when the solvent was THF.

Journal Article↗