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Showing papers in "Tetrahedron in 1980"


Journal ArticleDOI
TL;DR: In this article, a method for the rapid calculation of atomic charges in σ-bonded and nonconjugated π-systems is presented, where only the connectivities of the atoms are considered.

3,640 citations


Journal ArticleDOI
TL;DR: In this paper, a new coupling constant-torsion angle relation for the three-bond 1H-1H spin-spin coupling constant is formulated, which includes a correction for the electronegativity of substituents.

1,909 citations



Journal ArticleDOI
TL;DR: In this paper, stereo and regiochemical aspects of three reaction types: the SN2' reaction (bimolecular nucleophilic substitution with allylic rearrangement); displacement reactions effected by organometallic reagents; the conversion of allylic alcohols into halides.

326 citations



Journal ArticleDOI
TL;DR: Some of the more recent innovations and techniques which have been developed in the past 10-15 years around these features of carboxyl group chemistry are discussed in this article, with a review.

279 citations



Journal ArticleDOI

223 citations


Journal ArticleDOI
TL;DR: The Bischler-Napieralski dihydroisoquinoline synthesis from N-arylethyl-amides was proven to occur via the imidoyl chlorides and the corresponding nitrilium salt.

171 citations


Journal ArticleDOI
Konrad B. Becker1

167 citations


Journal ArticleDOI

Journal ArticleDOI
TL;DR: In this article, a synthese stereospecifique du p-tolylsulfinyl acetate de t-butyle is described, which permet de realiser, par une condensation du type aldol, des syntheses asymetriques de β-hydroxyacides avec des rendements chimiques de l'ordre de 80% and des taux d'induction generalementeleves (80a90%).


Journal ArticleDOI
TL;DR: Kinetic study of the formation and displacement steps has enabled the selection of substituents on the original pyrylium to optimise conditions for both steps for the selective conversion of primary amino groups into many other functionalities under mild conditions in high yields.

Journal ArticleDOI
TL;DR: In this article, the 13 C NMR spectra of twenty one iridoid glucosides and fourteen acyl IRD-glucosides of various cyclopentane oxidation states were analyzed and their carbon shifts assigned.

Journal ArticleDOI
TL;DR: In this paper, it was found that alkenylhydroquinone ethers can be demethylated with argentic oxide or ceric ammonium nitrate in the presence of 2,4,6-pyridinetricarboxylic acid as a catalyst and afforded ubiquinone-2, menaquinone-1 and their analogs in yields of 53 to 89%.

Journal ArticleDOI
Simon S. Jones1, B. Rayner1, Colin B. Reese1, Aiko Ubasawa1, M. Ubasawa1 
TL;DR: The use of the DBMB protecting group in oligoribonucleotide synthesis is described for the first time in this paper, where the first phosphorylation step (leading to phosphodiester intermediates) is carried out by treatment with o -chlorophenyl phosphorodi-(1,2,4-triazolide) (13a ; Ar = 2-C1C 6 H 4 ) and then with water and triethylamine.


Journal ArticleDOI
TL;DR: In this paper, the stereochemistry of the formation and breaking of cyclic cyclic phosphorus esters has been investigated and compared with analogous reactions in acyclic phosphoric esters, and it is suggested that nucleophilic substitutions at phosphorus are inherently stereospecific.

Journal ArticleDOI
TL;DR: In this paper, β-unsaturated γ-dicarbonyl compounds, easily obtained by reaction of pyridinium chlorochromate with alkylfurans, are interesting starting materials for the rapid synthesis of 3-oxo-cyclopentenes.


Journal ArticleDOI
TL;DR: In this paper, a stereoselective synthesis of highly optically pure enantiomers of δ-multistriatin (1 S,2 S,4 S,5 R )-2,4-dimethyl-5-ethyl-6, 8-dioxabicyclo[3.2] was accomplished starting from tartaric acid enantiomer.





Journal ArticleDOI
TL;DR: In this paper, the isolation of tetrahydrofurofuran lignans from the roots of A. absinthium and six closely related species is reported, all stereoisomers of 1- [(3,4-methylenedioxy-5-methoxy) phenyl]-4-(3, 4,5-trimethoxyphenyl)-tetrahydron-1H,3H-furo[3-4-c]furan, was found.

Journal ArticleDOI
TL;DR: The unsymmetrical N,N,N-trimethyl tris-indolobenzene 3 has been synthesized by several routes, including cyclotrimerization of the O-acetate of indoxyl.

Journal ArticleDOI
TL;DR: In this paper, Verschiedene Reaktandgases (CH 4, i -C 4 H 10, NO, N 2 O, Amine,Ather, (CH 3 ) 4 Si) wurden auf ihre Brauchbarkeit bei der bestimmung der Lage von Doppelbindungen durch chemische Ionisations-Massenspektrometrie untersucht.

Journal ArticleDOI
TL;DR: In this article, a mechanism involving the elimination of copper hydride to form a hetaryne intermediate was suggested, which yielded 2,2'-biindolyl after hydrolysis.