The potential of (33)S NMR spectroscopy for biochemical investigations on taurine (2-aminoethanesulfonic acid) is explored. It is demonstrated that (33)S NMR spectroscopy allows the selective and unequivocal identification of taurine in biological samples. (33)S NMR spectra of homogenated and intact tissues are reported for the first time, together with the spectrum of a living mollusc. Emphasis is placed on the importance of choosing appropriate signal processing methods to improve the quality of the (33)S NMR spectra of biological tissues.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A new method for the synthesis of conjugated polyenes containing up to eight double bonds with all-E configuration is reported. The procedure is based upon a homocoupling reaction of dienyl-, trienyl-, or tetraenylsilanes, promoted by PdCl(2) in methanol and in the presence of LiCl and CuCl(2). Configurational and conformational assignments were rigorously made on the basis of NMR spectra. The compounds obtained represent a novel interesting class of symmetrically substituted polyenes with potential optical and electrooptical properties. By changing the solvent, the homocoupling process can be switched to the halogenation of the silyl-substituted terminal double bond, thus leading to polyenyl halides.

Substituent effects on S-33 NMR parameters in 3-XC6H4SO3Na (X = NO2, NH3+, CF3, SO3-, OH, H, CH3, NH2, and O-) have been studied. The results obtained confirm that S-33 chemical shifts and line widths depend upon the electronic properties of substituents present on the aromatic ring. The trends observed are consistent with the behavior found for previously reported 4-substituted benzenesulfonates, whose list has been now enlarged to include ionic substituents (O-, NH3+, NH(CH3)(2)(+), SO3-). Dual substituent parameter analysis of S-33 nuclear quadrupole coupling constants using charged and uncharged substituents has been performed. A linear relationship between S-33 chemical shifts and nuclear quadrupole coupling constants demonstrates that in 3- and 4-substituted benzenesulfonates substituents affect S-33 NMR parameters in the same way, probably by expansion or contraction of p valence shell electrons around the sulfur nucleus. O-17 NMR data suggest that sulfur d orbitals are little effective in transmitting substituent effects.

Substituent effects on 1J(CO,C1) in methyl 4-X-benzoates 1 and 2,6-dimethyl-4-X-benzoates 2 appear to be related with chemical-shift variations at the two involved carbon nuclei rather than with pi-bond-order changes.

Both S-33 chemical shifts and line widths in 4-XC6H4SO3Na (X = NO2, COCH3, Cl, F, H, CH3, OH, NH2, NMe2) are strongly dependent on the electronic properties of substituents. The occurrence of a "reverse" chemical shift effect has been observed. The dual substituent parameter analysis of S-33 chemical shifts suggests that (i) inductive contribution predominates over the resonance one, (ii) resonance effects operate without direct conjugation between the aromatic ring and the sulfonate group, and (iii) variations of S-33 chemical shift seem to be attributable to -SO3- d-p pi-polarization. Variations of S-33 line widths can be primarily ascribed to a change in the nuclear quadrupole coupling constant values. The dual substituent parameter analysis of the nuclear quadrupole coupling constants seems to indicate that in 4-substituted benzenesulfonates substituent effects on the S-33 nuclear quadrupole coupling constants and chemical shifts have the same origin.

AbstractThe title compound (II) is prepared from 1,1,1‐trifluoropropanone (I) by a known procedure.

ChemInformVolume 18, Issue 33 Physical Organic Chemistry ChemInform Abstract: Oxygen-17 and Carbon-13 Identification of the Dimethyldioxirane Intermediate Arising in the Reaction of Potassium Caroate with Acetone. L. CASSIDEI, L. CASSIDEI Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorM. FIORENTINO, M. FIORENTINO Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorR. MELLO, R. MELLO Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorO. SCIACOVELLI, O. SCIACOVELLI Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorR. CURCI, R. CURCI Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this author L. CASSIDEI, L. CASSIDEI Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorM. FIORENTINO, M. FIORENTINO Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorR. MELLO, R. MELLO Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorO. SCIACOVELLI, O. SCIACOVELLI Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this authorR. CURCI, R. CURCI Fachbereich Pharm., Johannes-Gutenberg Univ. Mainz, D-6500 MainzSearch for more papers by this author First published: August 18, 1987 https://doi.org/10.1002/chin.198733049AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume18, Issue33August 18, 1987 RelatedInformation

The oxidation of organic sulphides (n-Bu2S, PhSCH3, Tolyl-SCH3, p-Cl-C6H4SCH3, and Ph2S by (HMPT)CrO(O2)2 1′ in CHCl3 has been studied. The reaction produces the corresponding sulphoxides in nearly quantitative yields according to a 2:1 stoichiometry of sulphide to metaldiperoxide. A second-order-overall (order one in each of the reagents) kinetic law is obeyed. In parallel, the oxidation of organic sulphides by (HMPT)MoO(O2)2 1' has been studied. Kinetic data, the observed rate laws, and the effect of inhibitors (HMPT, DABCO) have pointed out that-although 1' is significantly more reactive than 1′—considerable similarity exists between the two metaldiperoxides, in that both appear to act as electrophilic oxidizers. Also, through 1H, 31P and 13C NMR investigations have permitted to assess the relevance of equilibria (HMPT)MO(O22 MO(O2)2 + HMPT [with M = Mo(VI) or Cr(VI)]in solution, whereas no NMR evidence could be found for significant substrate coordination under the given conditions.

AbstractThe 33S NMR spectra of some selected sulphones demonstrate additive substituent‐induced chemical shift (SCS) effects. In dimethyl sulphone (1), replacement of a methyl group by a vinyl or a phenyl group causes an SCS effect of −7 to −8.5 ppm or −4 to −5 ppm, respectively. The 33S chemical shift in 1 is also sensitive to substitution of methyl protons. The ß‐substituent effect for methyl and phenyl groups is in the range +7 to +8 ppm and +5.5 to +6 ppm, respectively.

Arylation of 2-acetamidoacrylic acid using Pd(OAc)2/PPh3 or PdCl2 (PPh3)2 as catalytic systems leads to α-acetamidocinnamic acids of Z configuration.

AbstractThe 33S NMR spectra of some selected sulphones demonstrate additive substituent‐induced chemical shift (SCS) effects. In dimethyl sulphone (1), replacement of a methyl group by a vinyl or a phenyl group causes an SCS effect of −7 to −8.5 ppm or −4 to −5 ppm, respectively. The 33S chemical shift in 1 is also sensitive to substitution of methyl protons. The ß‐substituent effect for methyl and phenyl groups is in the range +7 to +8 ppm and +5.5 to +6 ppm, respectively.

An iterative analysis of the 19F NMR spectrum of octafluoronaphthalene has been performed. The more positive value of J12ortho compared with J23ortho is explained in term of π-bond fixation. For the inter-ring coupling constants, the Fermi contact term transmitted via π-electrons appears to be the predominant coupling mechanism. The Jperi value is in good agreement with the empirically predicted value starting from Jperi values in perfluoroazanapthalenes and taking into account the change in molecular geometry due to substitution of a N atom with a C atom.

Chemischer InformationsdienstVolume 13, Issue 10 Physical Organic Chemistry ChemInform Abstract: PCILO CALCULATION ON THE ANSA CONFORMATION OF HEXAHYDRORIFAMYCIN S. L. CASSIDEI, L. CASSIDEISearch for more papers by this authorM. MAESTRO, M. MAESTROSearch for more papers by this authorO. SCIACOVELLI, O. SCIACOVELLISearch for more papers by this author L. CASSIDEI, L. CASSIDEISearch for more papers by this authorM. MAESTRO, M. MAESTROSearch for more papers by this authorO. SCIACOVELLI, O. SCIACOVELLISearch for more papers by this author First published: March 9, 1982 https://doi.org/10.1002/chin.198210077AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume13, Issue10March 9, 1982 RelatedInformation

Chemischer InformationsdienstVolume 12, Issue 22 Physical Organic Chemistry ChemInform Abstract: CONFORMATIONAL ANALYSIS OF THE C(6)-O(1)-C(5)-C(4) FRAGMENT IN ACETYLCHOLINE BY CARBON-13 NMR SPECTROSCOPY L. CASSIDEI, L. CASSIDEISearch for more papers by this authorO. SCIACOVELLI, O. SCIACOVELLISearch for more papers by this author L. CASSIDEI, L. CASSIDEISearch for more papers by this authorO. SCIACOVELLI, O. SCIACOVELLISearch for more papers by this author First published: June 2, 1981 https://doi.org/10.1002/chin.198122067AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume12, Issue22June 2, 1981 RelatedInformation

Dialkenylcuprates, generated by addition of dialkylcuprates to acetylene, react with αβ-unsaturated sulphones to give cis-γδ-unsaturated sulphones which can be easily desulphonylated with retention of the double-bond configuration.

AbstractAcetylen (III) ergibt mit den Lithiumdialkylcupraten (II) die Lithiumdivinylcuprate (IV), die mit den α,β‐ungesättigten Sulfonen (I) zu den mö‐ungesättigten Phenylsulfonen (V) führen.

Fulvic and humic acids fractionated by gel chromatography on Sephadex G-50 have been investigated by 1 H NMR and i.r. spectroscopic techniques. Fulvic acid gives rise to only one significant fraction (FA-I) whose spectrum does not substantially differ from that of the unfractionated sample. The HA sample is separated into a high (HA-I, nominal mol. wt > 10,000) and a low molecular weight fraction (HA-II, nominal mol. wt 500–10,000). The two fractions show worthwhile differences in the 1 H NMR spectra. Signals belonging to protons of long-chain aliphatic hydrocarbons or acids are present only in the HA-I fraction, which also displays a lower content of aromatic protons than the HA-II fraction. The pattern of the broad and intense absorption in the range 2.9 and 5.0 ppm of the two spectra is different. On the basis of the i.r. spectra, it has been suggested that this might be due to a different distribution of structures as polysaccharides. It seems likely that the non-humic substances are trapped in the voids of the high molecular wight polymer. The results obtained indicate that humic fractions narrower than the original material still show a high degree of polydispersity. The overall percentage distribution of chemical structures in humic fractions with varying molecular weights is different.