Showing papers in "Tetrahedron in 1975"

TL;DR: One of the carbonyl functions of succinimides and glutarimides is selectively reduced by sodium borohydride in presence of hydrochloric acid yielding ω-carbinol-lactams as mentioned in this paper.

TL;DR: In this paper, a new stereoelectronic theory for the cleavage of the tetrahedral intermediate in the hydrolysis of esters and amides is presented, based on the orientation of the lone pair orbitals of the hetero-atoms.

TL;DR: In this paper, the absolute configurations of sulcatol enantiomers were established and key materials to study the relationship between pheromone activity and chirality were obtained from the enantiomer.

TL;DR: In this article, the synthesis of α-alkyl mercaptohippuric acid (3a-d), N-benzyloxycarbonyl-α-methylthioglycine (3e) and their methyl esters (5a−d) was described.

TL;DR: In this article, the Cu-catalysed condensations of 2-bromobenzoic acids with β-dicarbonyl anions to give α-arylated β-Dicaronyl compounds have been investigated in detail.

TL;DR: In this article, stable nitroxide radicals were obtained by the oxidation of 1-hydroxyindolines prepared by allowing the organo-metallic compounds to act upon 2-phenylisatogen and arylimino-derivatives.

TL;DR: In this article, complete assignments of chemical shifts and extensive assignments of carbon-proton coupling constants are presented for all the monohydroxycoumarins except the 5-derivative.

TL;DR: In this article, the carbonate dargent depose sur Celite oxyde les diols bisprimaires et primaires-tertiaires 1,4, 1,5 and 1,6 en lactones avec de tres bons rendements.

TL;DR: In this article, a procedure for the economic calculation of general conformational transition states is described which avoids exhaustive mapping of interconversion paths, which can be used for the calculation of symmetric transition states without using point-by-point mapping techniques.

TL;DR: In this paper, the authors described the isolation, partial characterization, and biological activity of a new mycotoxin from cultures of Penicillium roqueforti, and the name "PR toxin" was tentatively assigned to the compound.

TL;DR: This paper synthesized frontalin and its antipode from (R)-(+)-2-hydroxy-2-methylpentane-1,5-dioic acid 5→2 lactone.

TL;DR: In this paper, the authors count the number of classical valence structures in which the ring is formally represented by a Kekule benzene formula, and the ratio of this number and the total number for the molecule is suggested as a measure of benzenoid-like character of the ring considered.

TL;DR: In this article, the authors assigned structure 1a to pukalide, which is a constituent of an alcyonarian, on the basis of spectral data, and showed that it is diterpenoid with a cembrane skeleton, bearing butenolide, epoxide, isopropenyl, and an unprecedented α,α-disubstituted furan-β-carboxylate function.

TL;DR: In this paper, photo-induced double cyclodehydrogenation of bis-arylvinyl arenes was used to synthesize a helicene in one operational step by photoinduced doublecyclodehydrogens.

TL;DR: The method of predicting aromaticity based on simple Huckel calculations was applied to heterocyclic systems which contain the imine nitrogen in this article, and the necessary heteroatom integrals were determined from thermochemical data.

TL;DR: Isospectral molecules are nonidentical species whose molecular graphs have the same set of eigenvalues within HMO calculations as mentioned in this paper, and several new concepts and methods for constructing pairs of isosensorral graphs are discussed.

TL;DR: The reaction of cyclopentadienylthallium with chlorophosphines yields cyclopentaide phosphines 1, 4, 6 and 8 and some derivatives (oxides, sulfides and methyl iodides) have been prepared as mentioned in this paper.

TL;DR: In this article, the structures of eleven polyhalogenated monoterpenes from Plocamium cartilagineum have been determined by spectroscopic methods based on the 3,7dimethyl-1,5,7-octatriene skeleton.

TL;DR: In this article, a preparative sequence from 2,3 polymethylene-2-cyclopentenone 5 to 2,6-polymethylenebromobenzenes 3 (n = 6, 7, 10) and 2, 6 polymethylenephenyllithiums 6 has been found.

TL;DR: Stability of thiazolidine-4-carboxylic acids and chain tautomerism are studied in acidic, basic and neutral solution in this article, where it is suggested that this reaction may proceed through a sulfonium ion intermediate.

TL;DR: In this paper, a preference for α,γ-disubstitution of dinitro- and di-formyl porphyrins is established on the basis of their NMR spectra.

TL;DR: The structure elucidation of myrrhine (6), a novel base isolated from Myrrha 18- guttata, is reported in this article, where the biogenesis of the Coccinellidae defensive alkaloids is discussed and coccinelline is shown to be biosynthetized through the polyacetate pathway.

TL;DR: Sinulariolide, a novel diterpene lactone has been isolated from the alcyonarian Sinularia flexibilis as mentioned in this paper, and its structure has been determined by using spectroscopic and chemical methods.

TL;DR: Treatment of 16 α-amino acid esters with isoamyl nitrite in the presence of a small amount of organic acid in chloroform or benzene, followed by chromatographic purification on alumina was found to afford the corresponding α-substituted-α-diazo esters in fairly good yields.

TL;DR: In this article, the optically active amino acids and the dl -mixture were polymerised by the mixed anhydride procedure to give polymers which showed no evidence of base stacking or of interaction with polyadenylic acid.

TL;DR: In this paper, the electrochemical oxidation of seven different nitroxyl radicals has been investigated in acetonitrile at a platinum electrode, and the electrostatic solvation enthalpies of two oxammonium ions were calculated.

TL;DR: Kidamycin represents a new type of polycyclic C-glycosyl microbial metabolites and is elucidated by means of chemical studies as well as an X-ray analysis.

TL;DR: The thermal cracking of phenol 1-14 C and tritiated in specific positions has been studied at atmospheric pressure between 665 and 865°C with a contact time of 2·5 seconds, suggesting the most probable reactions occuring during the thermal cracking.