bluuebunny/crossref_metadata_2025 huggingface dataset:
The Bacterial Ribosome: A Programmed Enzyme
Authors: Gassen Hans Günter
Published: December 2003

Ribosome‐dependent protein synthesis in bacteria represents a complex sequence of reactions involving more than 150 compounds. The ribosome, constructed from 53 individual proteins and 3 nucleic acids, functions as the enzyme which catalyzes peptide bond formation. In contrast to most known enzymes the ribosome is “programmed” by the mRNA–the short‐lived transcript of DNA. The ribosome reads the nucleotide message of the mRNA and transforms its information into the amino acid sequence of a protein. In the course of this process, chemical bond energy is converted into directed mechanical motion. The model of protein biosynthesis on the programmable ribosome provides answers to the following questions: how is the mRNA framed into information units, how is the substrate specificity of the ribosome modulated by the codon of the mRNA, and how does the mRNA move with respect to the ribosome by one trinucleotide per peptide bond formed?
Palladacycloalkanes by Oxidative Coupling of 3,3‐Dimethylcyclopropene with Palladium(0) Compounds
Authors: Binger Paul , Büch Holger Michael , Benn Reinhard , Mynott Richard
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 153. DOI:10.1002/anie.198201530
Convenient General Synthesis of Alkynylcyclopropanes
Authors: Liese Thomas , de Meijere Armin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 34. DOI:10.1002/anie.198200340
α,β‐Unsaturated Ketones by Cathodic Addition of Benzotrichloride to Ketones
Authors: Steiniger Michael , Schäfer Hans J.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 137. DOI:10.1002/anie.198201370
Cationic Prenylation of Olefins
Authors: Klein Herbert , Erbe Anne , Mayr Herbert
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 105. DOI:10.1002/anie.198201050
Evolution of Hydrogen from Photochemically Reduced Water‐Soluble Tin(IV)‐Porphyrins
Authors: Krüger Wolfgang , Fuhrhop Jürgen‐Hinrich
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 193. DOI:10.1002/anie.198201930
The Dianion 1,2,3,4‐Tetraphenylcyclobutadienediide
Authors: Boche Gernot , Etzrodt Heinz , Marsch Michael , Thiel Walter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 355. DOI:10.1002/anie.198203550
Stereospecific Synthesis of (S,S)‐Palythazine from D‐Glucose
Authors: Jarglis Pan , Lichtenthaler Frieder W.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 175. DOI:10.1002/anie.198201750
Metal Hexamethoxides
Authors: Jacob Eberhard
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 317. DOI:10.1002/anie.198203170
Cyclopropenes as Complex Ligands: Fe2(CO)9‐Induced Ring‐Opening of a Spirocyclopropene and Reversible CO‐Addition to the Vinylcarbene Ligand
Authors: Klimes Jörg , Weiss Erwin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 477. DOI:10.1002/anie.198204770
The Cycloaddition of Carbonyl‐Flanked Methylene Bridges—A Novel Method for the Synthesis of Metallacycles
Authors: Bauer Christine , Guggolz Ernst , Herrmann Wolfgang A. , Kriechbaum Gangolf , Ziegler Manfred L.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 434. DOI:10.1002/anie.198204340
(A→D) Ring Closure to the Nickel(II)‐B,C,D‐Hexadehydrocorrinate
Authors: Montforts Franz‐Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 499. DOI:10.1002/anie.198204990
Ph(Me3Si)CPCl as Educt for Methylenephosphanes with Alkyl‐, Amino‐, Phosphino‐, Alkoxy‐, or Alkylthio‐Groups on Phosphorus
Authors: Appel Rolf , Kündgen Ursula
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 549. DOI:10.1002/anie.198205490
Hexagonal Ferrites from Melts and Aqueous Solutions, Magnetic Recording Materials
Authors: Hibst Hartmut
Published: December 2003

Owing to their particular crystallographic properties, ferrimagnetic hexagonal ferrites exhibit a far greater coercive force than the conventional magnetic pigments. They therefore appear to be suitable for use in magnetic information storage procedures, some of which are novel and are at the development stage. Thus, magnetic tapes of high coercive force containing barium ferrite could be used as master tapes for copying magnetic information or for producing forgery‐proof magnetic cards, if magnetic heads having high‐order write fields were successfully developed. Moreover, platelet‐like ferrite pigments in which the preferred direction of magnetic orientation is perpendicular to the plane of the platelet are of great interest for perpendicular magnetic recording.

In this progress report, the crystal structures, magnetic characteristics of hexagonal ferrites, and chemical processes for their production are discussed. In particular, reactions in salt melts or under hydrothermal conditions produce finely divided pigments whose particles have a pronounced hexagonal, plate‐like habit, a narrow particle size distribution, and advantageous magnetic properties. The magnetic properties of the pigments crystallized from salt melts may be adjusted by cation exchange.
A Novel Anionic Five‐Coordinate Tris(trichlorostannato)platinum(II) Complex
Authors: Albinati Alberto , Nägeli Ralph , Rüegger Heinz , Pregosin Paul S.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 755. DOI:10.1002/anie.198207550
One‐Pot Synthesis of 1‐Alken‐5‐yne Derivatives
Authors: Priebe Hanno , Hopf Henning
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 635. DOI:10.1002/anie.198206350
2‐Methyl‐2‐triphenylphosphoniodithiopropionate–A Photosensitive Complex Ligand with Labile PC Bond
Authors: Kunze Udo , Merkel Reinhard , Winter Werner
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 711. DOI:10.1002/anie.198207110
The 1,3‐Dithian‐2‐ylmethoxycarbonyl (Dmoc) Moiety–A Protecting Group for the Amino Function in Peptide Synthesis
Authors: Barthels Regina , Kunz Horst
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 702. DOI:10.1002/anie.198207020
Influence of Conformational Rigidity on the Stabilization of α‐Ferrocenyl Carbocations: A cis‐Fixed Diferrocenyl Carbenium Ion
Authors: Mueller‐Westerhoff Ulrich T. , Nazzal Adel , Prössdorf Wolfram , Mayerle James J. , Collins Russell L.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 686. DOI:10.1002/anie.198206860
Diels‐Alder Reactions of [5]Metacyclophane
Authors: Turkenburg Lucas A. M. , Blok Pieter M. L. , de Wolf Willem H. , Bickelhaupt Friedrich
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 744. DOI:10.1002/anie.198207440
Bicyclo[4.4.2]dodeca‐1‐ene– The First “Hyperstable” Bridgehead Olefin
Authors: Kukuk Hanspeter , Proksch Ehrhardt , de Meijere Armin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 696. DOI:10.1002/anie.198206960
Synthesis, Structure, and Reactions of Primary Adducts of Sulfur or Selenium with Hexaphenylcarbodiphosphorane
Authors: Schmidbaur Hubert , Zybill Christian E. , Neugebauer Dietmar
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 590. DOI:10.1002/anie.198205900
Anomalies of Liquid Water
Authors: Lang Elmar Wolfgang , Lüdemann Hans‐Dietrich
Published: December 2003

Water at low temperatures (T < 300 K) reveals a multitude of unusual physico‐chemical properties, which originate from the strong directivity of the hydrogen bonds. This directivity forces the molecules into a tetrahedral arrangement of first neighbors and thus leads to a poor packing efficiency. All anomalies of the liquid become more pronounced in the metastable range below the melting pressure curve. In the following article, methods for the investigation of the supercooled range are presented. A few anomalous static and dynamic properties are described and compared with the properties of normal liquids. The experimental results are discussed in the context of computer simulations and the more recent theories on cold water. It can be concluded that the anomalies of water, for instance the density maximum of the liquid phase and the initial decrease in viscosity with pressure, are confined to the pT‐range: T < 300 K, p ≲ 200 MPa. At these pressures, lowering the temperature leads to an unexpected behavior of almost all physical properties. They seem to approach a phase transition at T ≃ (TM − 50 K), the nature of which has not yet been fully characterized. This phenomenon has hitherto been observed only in supercooled water.—In the future it will be possible to use supercooled aqueous solutions for kinetic studies, thus expanding the available dynamic range for the investigation of aqueous solutions considerably.
Topical Problems in the Biosynthesis of Red Blood Pigment
Authors: Franck Burchard
Published: December 2003

Uroporphyrinogen III plays a key role in the biosynthesis of heme, the red pigment of blood. In vivo studies with specifically 14C‐ and 3H‐labeled precursors have revealed that the formation uroporphyrinogen III in the organism follows several primary and subsidiary pathways. Model experiments on the pattern of biosynthesis have led to simple and effective methods of synthesizing uroporphyrin analogs and have shown that their production is strongly favored thermodynamically. The biologically porphyrins important thus available permit a mechanistic explanation of the light‐induced dermatoses in porphyria diseases and suggest promising medical applications in diagnosis and therapy.
Influence of Ring‐Size of Cycloalkenes on the Activation Volume in the High‐Pressure Copolymerization of Maleic Anhydride
Authors: Jenner Gérard , Kellou Mohamed , Papadopoulos Mihalis
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 929. DOI:10.1002/anie.198209290
Sterically Crowded Ethanes and Ethenes from Tri‐tert‐butylsilylmethyl Carbenoids
Authors: Weidenbruch Manfred , Flott Hermann
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 973. DOI:10.1002/anie.198209730
Black Lipid Membranes from Polymerizable Lipids
Authors: Benz Roland , Prass Werner , Ringsdorf Helmut
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 869. DOI:10.1002/anie.198208690
Regioselective Acylamination by Hetero‐Cope Rearrangement
Authors: Höfelmeier Richard , Blechert Siegfried
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 934. DOI:10.1002/anie.198209340
Diastereoselective Homoaldol Reaction with a (1‐Oxycrotyl)aluminum Compound, a Homoenolate Equivalent of n‐Butanal
Authors: Hoppe Dieter , Lichtenberg Florian
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 961. DOI:10.1002/anie.198209610
Stereospecific Synthesis of Palladium(II) Complexes of Macrocyclic Tetradentate Phosphane Ligands
Authors: Bartsch Rainer , Hietkamp Sibbele , Morton Stephen , Stelzer Othmar
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 807. DOI:10.1002/anie.198208070
Preparation of a Graphite Fluoride Film on Aluminum
Authors: Yamada Hiroaki , Nakajima Tsuyoshi , Watanabe Nobuatsu
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 939. DOI:10.1002/anie.198209390
CH4 Activation by Photoexcited Cu2 Molecules
Authors: Ozin Geoffrey A. , Mitchell Steven A. , García‐Prieto Jamie
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 798. DOI:10.1002/anie.198207980
New Possible Applications of Heavy Main‐Group Elements in Organic Synthesis
Authors: Kauffmann Thomas
Published: December 2003

Aside from elements of the 2nd row, and one element of the 3rd row of the periodic system—Si, P, S, and Se, respectively, whose organoelement groups such as Me3Si and Ph3P⊕have proven useful in numerous organic syntheses—other elements of the 3rd as well as 4th and 5th row (Ge, As, Sn, Sb, Te, Pb, Bi) can also be used as components of synthetically useful organoelement groups, the elements As, Sn, and Pb, in particular, offering certain advntages over the others. Some of these organoelement groups are suitable equivalents for Li‐ or halogen‐substituents attached to carbon; they stabilize carbanionic centers (minimum of this effect at the 3rd‐row elements), and owing to their suitability as leaving groups in β‐eliminations, also open up interesting synthetic possibilities. The thermally unducedsyn‐ and silica‐gel inducedanti‐elimination of Ph3Sn, Ph2Sb, Ph3Pb, together with β‐OH, are novel. With the newly synthesized compounds PhnEl—Ch2—Li (El = Sn, Pb, As, Sb, Bi) and other α‐ and β‐lithiated RnEl‐ and Ph2As(O)‐reagents such organoelement groups can be introduced into organic compounds and exploited in organic and organoelement synthesis.
Carbonyliron‐Assisted Cycloaddition of a 1,3‐Diene to a CC Double Bond: Synthesis of an Anthracyclinone Precursor
Authors: Vioget Philippe , Vogel Pierre , Roulet Raymond
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1128. DOI:10.1002/anie.198211280
Laser Photolysis—A New Route for Charge Separation
Authors: Kaupp Gerd , Jostkleigrewe Ernst
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1089. DOI:10.1002/anie.198210890
Synthesis and Properties of [2,3‐Bis(trimethylsilyl)‐2‐cyclopropen‐1‐yl]‐diazomethane
Authors: Maier Günther , Hoppe Manfred , Reisenauer Hans Peter , Krüger Carl
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1061. DOI:10.1002/anie.198210610
Radical Ion‐Pairs as Intermediates in Reactions of Tetra‐tert‐butyltetrahedrane and Tetra‐tert‐butylcyclobutadiene
Authors: Maier Günther , Schneider Klaus‐Albert , Malsch Klaus‐Dieter , Irngartinger Hermann , Lenz Andrea
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1072. DOI:10.1002/anie.198210720
1‐Phenylazulene → 2‐Phenylazulene Rearrangement—Substituent Migration or Skeletal Rearrangement?
Authors: Zeller Klaus‐Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1016. DOI:10.1002/anie.198210160
Trialkylsily(trifluoromethyl)diazenes as Tailored Reagents for Nucleophilic Trifluoromethylation
Authors: Hartkopf Uwe , de Meijere Armin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1121. DOI:10.1002/anie.198211210
The Chemical Behavior of Multibridged [2n] Cyclophanes
Authors: Kleinschroth Jürgen , Hopf Henning
Published: December 2003

Multibridged [2n] cyclophanes comprise a novel class of aromatic compounds, in which two benzene rings are connected by three up to a maximum of six ethano bridges. Compared to classical nonannelated arenes, their most distinct chemical property is the ease with which, particularly the higher‐bridged homologs, take part in addition reactions (Diels‐Alder additions, hydrogenations, and ionic additions). On the other hand, the typical regenerative behavior of aromatic molecules is not fully suppressed in the [2n]cyclophanes as evidenced by such typical electrophilic aromatic substitution reactions as bromination, Friedel‐Crafts acylation, and nitration. Besides these reactions in which the benzene rings are either destroyed or retained, reactions at and with the ethano bridges, e.g. their cleavage, isomerization, and functionalization can also occur.
(Oxamidoximato)(oxamidoxime)platinium(II) 7,7,8,8‐Tetracyanoquinodimethanide: A Crystal Structure with Segregated Parallel Stacks
Authors: Endres Helmut
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1309. DOI:10.1002/anie.198213090
Constitution of the Deferriform of the Albomycins δ1, δ2 and ε
Authors: Benz Günter , Schröder Theo , Kurz Jürgen , Wünsche Christian , Karl Wolfgang , Steffens Gerd , Pfitzner Jörg , Schmidt Delf
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1322. DOI:10.1002/anie.198213220
1‐Acetoxycarbapenems
Authors: Koller Wolfgang , Linkies Adolf , Pietsch Hartmut , Rehling Herbert , Reuschling Dieter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1193. DOI:10.1002/anie.198211930
3‐Hydroxy‐2‐(1,2,4‐triazol‐1‐yl)acrylic Acid Ethyl Ester and O‐Functional Derivatives
Authors: Maier Thomas , Cavagna Friedrich
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1246. DOI:10.1002/anie.198212460
Anomalous Reaction of Hydrazine with β‐Aminovinyl Ketones
Authors: Kunstmann Rudolf , Paulus Erich F.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1265. DOI:10.1002/anie.198212650
Synthesis of Bicyclic β‐Sultams
Authors: Cavagna Friedrich , Koller Wolfgang , Linkies Adolf , Rehling Herbert , Reuschling Dieter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1201. DOI:10.1002/anie.198212010
Fourfold Bridging of the Benzene Ring in One Step
Authors: Klieser Brigitte , Vögtle Fritz
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1392. DOI:10.1002/anie.198213920
o‐ and m‐Phenylenebis(dischlorophosphane)—Versatile, Useful Synthetic Building Blocks
Authors: Drewelies Kurt , Latscha Hans Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1416. DOI:10.1002/anie.198214160
Isocyanates as Universal Reagents for the Formation of Derivatives for Gas Chromatographic Enantiomer Separation
Authors: Benecke Ingrid , König Wilfried A.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1605. DOI:10.1002/anie.198216050
Prostacyclin and Synthetic Analogues
Authors: Bartmann Wilhelm , Beck Gerhard
Published: December 2003

The prostanoids continue to attract a great deal of attention, particularly in the pharmacological sector. Many of the numerous biological studies on prostaglandins deal with their cardiovascular effects. The pronounced antihypertensive and platelet aggregation‐inhibiting properties of prostacyclin (PGI2) resulted in world‐wide efforts to synthesize acid‐stable analogues of the natural product. Whereas refined analytical procedures disproved the hypothesis that PGI2 is a circulating hormone, exploratory human trials with PGI2 confirmed the pharmacological findings obtained from animal experiments. Clinical studies of PGI2 analogues have been started. In vitro studies on isolated vessels revealed that potent cardiovascular drugs stimulate prostacyclin synthesis; however, it has not as yet been possible to demonstrate whether these effects are also of therapeutic significance. A survey of the PGI2 analogues synthesized so far is presented, and, with the aid of a few examples, the problems encountered during their synthesis are outlined; structure‐activity relationships are also discussed.
Reversible O2‐Addition to Polymeric Schiff‐Base Complexes of VII and MnII and Their Use as Oxidation Catalysts
Authors: Sawodny Wolfgang , Grünes Reinhard , Reitzle Helmut
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1662. DOI:10.1002/anie.198216620

For corrigendum see DOI:10.1002/anie.198302581
Oxidative Cleavage of Benzyl Esters with Triarylamine Cation Radicals—Selective Deblocking of Protected Carboxy Functions
Authors: Dapperheld Steffen , Steckhan Eberhard
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1730. DOI:10.1002/anie.198217300
Tricarbonyl‐2,7‐methanoaza[10]annulenechromium(0)
Authors: Hilken Günter , Kinkel Tonio , Schwamborn Michael , Lex Johann , Schmickler Hans , Vogel Emanuel
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1622. DOI:10.1002/anie.198216220
Stetter's Complexes are no Intramolecular Inclusion Compounds
Authors: Hilgenfeld Rolf , Saenger Wolfram
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1690. DOI:10.1002/anie.198216900
Chiral Binuclear Carbene Complexes from (R,R)‐1‐(1‐Dimethylaminoethyl)‐2‐lithioferrocene and Hexacarbonyltungsten
Authors: Herrmann Rudolf , Ugi Ivar
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1630. DOI:10.1002/anie.198216300
Novel Synthetic Building Blocks Activated by Ring Strain: General Entry to 2‐Chloro‐2‐cyclopropylidene Acetates
Authors: Liese Thomas , Splettstösser Gisela , de Meijere Armin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1715. DOI:10.1002/anie.198217150
Reactivity by Ring Strain: Spirocyclopropyl‐Annelated Tricyclic Skeletons by a One‐Pot Three‐Step Reaction
Authors: Spitzner Dietrich , Engler Anita , Liese Thomas , Splettstösser Gisela , de Meijere Armin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1722. DOI:10.1002/anie.198217220
Asymmetric Synthesis of Methyl Jasmonate
Authors: Quinkert Gerhard , Adam Friedhelm , Dürner Gerd
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1777. DOI:10.1002/anie.198217770
New Dihydropyrans: Lewis Acid Catalyzed Cycloadditions of α,β‐Unsaturated Acyl Cyanides to Simple, Unactivated Olefins and Dienes: A Readily Accessible Route to Derivatives of Rose Oxide
Authors: Ismail Zeinhom M. , Hoffmann H. M. R.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1819. DOI:10.1002/anie.198218190
[Fe3W3S14]4−, A Novel Hexanuclear, “Pure” Bimetal‐Sulfur Cluster with Fe3(μ3‐S)2 Center
Authors: Müller Achim , Hellmann Winfried , Bögge Hartmut , Jostes Rainer , Römer Michael , Schimanski Uwe
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1757. DOI:10.1002/anie.198217570
Synthesis of Pd(η2‐CH2C5Me4)L2: Formation of a Fulvene Ligand by Metal‐Assisted H‐Shift from Pentamethylcyclopentadienyl
Authors: Kraus Hans‐Jürgen , Werner Helmut
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1793. DOI:10.1002/anie.198217930
The Sulfonation of Aromatic Isocyanates: Sulfonated p‐Tolyl Isocyanate—An X‐Ray Structure Analysis
Authors: Ballé Gerhard , Born Liborius , Dieterich Dieter , Petinaux Marcel , Reiff Helmut
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1875. DOI:10.1002/anie.198218750
Norcaradiene Valence Tautomer of a 1,6‐Methanol[10]annulene: Tricyclo[4.4.1.01,6]undeca‐2,4,7,9‐tetraene‐11,11‐dicarbonitrile
Authors: Vogel Emanuel , Scholl Thomas , Lex Johann , Hohlneicher Georg
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1882. DOI:10.1002/anie.198218820
A Novel Route to Phloroglucinols ‐ Synthesis, Structure, and Reactions of [n](2,4)Phloroglucinophanes
Authors: Effenberger Franz , Schönwälder Karl‐Heinz , Stezowski John J.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1833. DOI:10.1002/anie.198218330
Cyclobutadienes or Acetylenes from (2‐Cyclopropen‐1‐yl)carbenes—A Question of Spin Multiplicity?
Authors: Eisenbarth Philipp , Regitz Manfred
Published: December 2003

The complete manuscript of this communication appears in:Angew. Chem. Suppl. 1982, 2016. DOI:10.1002/anie.198220160
A μ2‐η2‐Styryl Complex by Reaction of Cp2Mo2(CO)4 with the Wittig Reagent (C6H5)3PCH2
Authors: Endrich Klaus , Korswagen Richard , Zahn Thomas , Ziegler Manfred L.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1906. DOI:10.1002/anie.198219060
Organometallic Compounds of Titanium and Zirconium as Selective Nucleophilic Reagents in Organic Synthesis
Authors: Weidmann Beat , Seebach Dieter
Published: December 2003

The addition of carbanionic organometallic compounds (usually RLi or RMgX) to a carbonyl group—a key step in numerous syntheses—is not always straightforward. Depending on the substrate, various complications and problems may arise, but in many cases these can be remedied by addition of (RO)3TiCl, (RO)3ZrCl or (R2N)3TiX to the classic lithium and Grignard reagents. This usually leads to formation of stable organo‐titanium and ‐zirconium compounds which react highly selectively with carbonyl groups. For example, CH3Ti(OiPr)3 reacts five orders of magnitude faster with benzaldehyde than with acetophenone at room temperature; reagents of the type RTi(OiPr)3 add smoothly to nitro‐, ido‐, or cyano‐subsituted benzaldehyde, and the reactions may be performed in chlorinated solvents or acetonitrile; the zirconium analogues have particularly low basicity and add in high yield to α‐ and β‐tetralones or to substrates containing a nitroaldol group; the inclusion of chiral OR* groups gives enantioselective reagents (up to 90% ee); allylic (RO3)Ti‐ derivatives react only at the more highly substituted carbon atom and, in addition, react diastereoselectively (up to 98% ds) with unsymmetrical ketones. Finally, titanium reagents have also been found to effect novel transformations such as direct geminal dialkylation (CO→CMe2) and alkylative amination [CO→CR(NR)]. The modification and finetuning (“taming”) of carbonyl reactivity obtainable by use of the new reagents is not dearly bought; starting materials are the cheap and harmless “titanates”, “zirconates” and the corresponding tetrachlorides.
Novel One‐Step Synthesis of Oxocyclopentanecarboxylates by Electrochemical Reduction of Cinnamic Acid Esters
Authors: Nishiguchi Ikuzo , Hirashima Tsuneaki
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 70. DOI:10.1002/anie.198300700
Transition‐Metal Substituted Stibanes as Acceptors: Cp(CO)(L)FeSbBr2 · PMe3 (L = CO, Me3P, MeNC)— 1 : 1‐Ferriostibane‐Trimethylphosphane Complexes
Authors: Kaul Hans‐Achim , Greissinger Dieter , Malisch Wolfgang , Klein Heinz‐Peter , Thewalt Ulf
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 47. DOI:10.1002/anie.198300470
Diastereo‐ and Enantioselective Synthesis of (1R,3R)‐Caronaldehyde Acid Methyl Ester and (1R,3R)‐Chrysanthemic Acid Methyl Ester from (R)‐Glycerinaldehyde Acetonide
Authors: Mulzer Johann , Kappert Michael
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 23. DOI:10.1002/anie.198300230
Expansion of Three‐Membered Heterocycles to Five‐Membered Cyclic Carbenes—Novel Reactions of Aziridine, Oxirane, and Thiirane with CO and CS Ligands in Iron, Ruthenium, and Manganese Complexes
Authors: Singh Mono M. , Angelici Robert J.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 184. DOI:10.1002/anie.198301840
Dye Diffusion Systems in Color Photography
Authors: Van de Sande Christian C.
Published: December 2003

Dye diffusion instant color photography has been a commercial success ever since its introduction in 1963. No doubt this is partly due to the spectacular nature of this innovation, and for the same reason it has never really rid itself of its gadget image. Moreover, the picture quality was inferior to that of traditional color photography. Photographic materials are now available whose image quality approaches that of the traditional color print. It is not well known that chemistry, and organic chemistry in particular, is the cornerstone of these new photographic products. Insights from this field have spurred creativity, not only in the fields of dye and polymer chemistry, but above all in the search for more efficient and, hopefully better, dye diffusion transfer systems. The result of all these efforts is a finely tuned microscale chemical factory which continues to open rewarding perspectives for the photographic industry.
Allyl(hydrido)platinum(II)‐Catalyzed Partial Hydrogenation of Dienes
Authors: Bertani Roberta , Carturan Giovanni , Scrivanti Alberto
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 228. DOI:10.1002/anie.198302280
The Structure of Tris(diphenylthiophosphinoyl)methanide, a Mesomerically Stabilized Carbanion
Authors: Grim Samuel O. , Gilardi Richard D. , Sangokoya Samuels A.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 271. DOI:10.1002/anie.198302710
Formation, Structure, and Synthetic Use of Gluco‐ and Galactopyranoside Acetophenone Acetals with 1,3‐Dioxane Rings
Authors: Lipták András , Fügedi Péter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 254. DOI:10.1002/anie.198302540
Magic‐Angle‐Spinning NMR (MAS‐NMR) Spectroscopy and the Structure of Zeolites
Authors: Fyfe Colin A. , Thomas John M. , Klinowski Jacek , Gobbi Gian C.
Published: December 2003

After outlining the chemical features and properties which make zeolites such an important group of catalysts and sorbents, the article explains how high‐resolution solid‐state NMR with magic‐angle spinning reveals numerous new insights into their structure.29Si‐MAS‐NMR readily and quantitatively identifies five distinct Si(OAl)n(OSi)4‐nstructural groups in zeolitic frameworks (n = 0, 1,….4), corresponding to the first tetrahedral coordination shell of a silicon atom. Many catalytic and other chemical properties of zeolites are governed by the short‐range Si, Al order, the nature of which is greatly clarified by29Si‐MAS‐NMR. It is shown that, as expected from Pauling's electroneutrality principle and Loewenstein's rule, both in zeolite X and in zeolite A (with Si/Al = 1.00) there are no AlOAl linkages. In zeolite A and zeolite X with Si/Al = 1.00 there is strict alternation of Si and Al on the tetrahedral sites. Ordering models for Si/Al ratios up to 5.00 (in zeolite Y) may also be evaluated by a combination of MAS‐NMR experiments and computational procedures.29Si‐MAS‐NMR spectra reveal the presence of numerous crystallographically distinct Si(OSi)4sites in silicalite/ZSM‐5, suggesting that the correct space group for these related porosilicates is not Pnma.27Al‐MAS‐NMR clearly distinguishes tetrahedrally and octahedrally coordinated aluminum, proving that, contrary to earlier claims, Al in silicalite is tetrahedrally substituted within the framework. In combination,29Si‐ and27Al‐MAS‐NMR is a powerful tool for monitoring the course of solid‐state processes (such as ultrastabilization of synthetic faujasites) and of gas‐solid reactions (dealumination of zeolites with silicon tetrachloride vapor at elevated temperatures). They also permit the quantitative determination offrameworkSi/Al ratios in the region 1.00 < Si/Al < 10 000. Since most elements in the periodic table may be accommodated within zeolite structures, either as part of the exchangeable cations or as building units of the anionic framework, there is immense scope for investigation by MAS‐NMR and its variants (cross‐polarization, multiple pulse and variable‐angle spinning) of bulk, surface and chemical properties. Some of the directions in which future research in zeolite science may proceed are adumbrated.
Seleno‐ and Telluroformaldehyde as Bridging Ligands in Organometallic Complexes
Authors: Herrmann Wolfgang A. , Weichmann Josef , Serrano Ricardo , Blechschmitt Klaus , Pfisterer Heike , Ziegler Manfred L.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 363. DOI:10.1002/anie.198303630
[Co3{μ3‐S}{o‐(SCH2)2C6H4}3]2−: The First Trinuclear Cobalt Cluster with Tetrahedral CoS4‐Coordination
Authors: Henkel Gerald , Tremel Wolfgang , Krebs Bernt
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 307. DOI:10.1002/anie.198303070
Electromicrobial Reduction Using Yeasts
Authors: Günther Helmut , Frank Cornelia , Schuetz Hans‐Jürgen , Bader Johann , Simon Helmut
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 463. DOI:10.1002/anie.198304630
From Environmental Analytical Chemistry to Ecotoxicology—A Plea for More Concepts and Less Monitoring and Testing
Authors: Stumm Werner , Schwarzenbach René , Sigg Laura
Published: December 2003

The development of cultural and technical civilization has been marked with increasing interference in hydrogeochemical cycles and the production of a growing number of chemicals; this is accompanied by a growing concern on the potential adverse effects of chemicals on biological systems. Assessment of the potential toxicological and ecological effects of pollutants is of central importance. We are of the opinion that this cannot be accomplished by merely evaluating the harmfulness of a substance on the basis of toxicity tests with individual organisms and by monitoring analytically the environment for pollutants. We would like to encourage chemists to participate in the solution of ecotoxicological problems: chemodynamical concepts permit the estimation‐on the basis of physical‐chemical generalizations and with the help of compound‐specific data‐of the fate, the distribution, the potential for bioaccumulation in the food chain, and the approximate residence time of pollutants (and thus the attainable residual concentrations) in the environment and therefore to predict the relative risk of different pollutants.
The Tricyclo[9.3.1.03,8]pentadecane System— A Short Synthesis of a C‐Aromatic Taxane Skeleton
Authors: Shea Kenneth J. , Davis Peter D.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 564. DOI:10.1002/anie.198305640
The Zirconocene‐Induced Coupling of Butadiene with Carbonyl Compounds
Authors: Erker Gerhard , Engel Klaus , Atwood Jerry L. , Hunter William E.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 675. DOI:10.1002/anie.198306750
(PhCCLi)4(tmhda)2, A Polymeric Organolithium Compound with cubic Li4C4 Structural Units
Authors: Schubert Bernd , Weiss Erwin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 703. DOI:10.1002/anie.198307030
A Quarter Century of Thin‐Layer Chromatography—An Interim Report
Authors: Stahl Egon
Published: December 2003

Thin‐layer chromatography (TLC) has been in general use since 1958. The prerequisites were the use of very small particle size material in the layers and the demonstration that not only lipophilic mixtures but also mixtures of cardiac glycosides, alkaloids, sugars, and amino acids could be separated quickly and simply on silica gel layers. The impressive separations obtained using the method later encouraged attempts to use adsorbants having such, narrow‐range small particles in column chromatography. In order to achieve sufficient flow rates the use of high pressures was necessary. Thus, high pressure or high performance liquid chromatography (HPLC) was born, whose godfather, as far as instrumental development is concerned, was gas chromatography (GC). Today, chromatography is classified according to the nature of the transport phase: liquid, gas, or “electro” chromatography. Sample preparation often requires more time than the actual separation. rapid thermal separation and application techniques (TAS, TFG) have brought advantages to TLC. As before, the art of chromatography consists in choosing the appropriate mobile phase, stationary phase, and separation technique. Gradient TLC offers new possibilities; for example, gradient layers make it possible to obtain selective information on the individual components of a mixture and also allow significant focussing effects to be achieved. Sequential and centrifugal TLC have paved the way for further advances. The questions arise whether the standard conditions, formulated 25 years ago, are still applicable and how the variations which have been introduced should be judged. Group‐ and substance specific methods of detection are discussed in addition to universal methods. Quantitation is critically discussed and it is concluded that HPLC has the better chance in the furture. Combination and coupling techniques ease the positive identification of individual substances. Finally, it is discussed why TLC is the simplest, most versatile, most cost effective, and most widely used chromatographic method and reasons are proposed as to why it will remain so for the foreseeable future.
2‐Phosphaallyl Cations by Formal Insertion of P⊕ into the CC Double Bond
Authors: Schmidpeter Alfred , Lochschmidt Siegfried , Willhalm Angela
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 710. DOI:10.1002/anie.198307100
A New Phytohormone from Mimosa pudica L.
Authors: Schildknecht Hermann , Bender Wolfgang
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 818. DOI:10.1002/anie.198308180
Synthesis of Acylpolyamines: Acetylspermidines and C12:0‐Acarnidine
Authors: Boukouvalas John , Golding Bernard T. , McCabe Richard W. , Slaich Pritpal K.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 860. DOI:10.1002/anie.198308600
η6‐Bonded Alkylbenzenes as Novel Bridging Ligands in Dinuclear Complexes of Iron and Cobalt
Authors: Jonas Klaus , Koepe Gerd , Schieferstein Ludwig , Mynott Richard , Krüger Carl , Tsay Yi‐Hung
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 920. DOI:10.1002/anie.198309200
Stereoselective Synthesis of Enantiomerically Pure Natural Products—Estrone as Example
Authors: Quinkert Gerhard , Stark Herbert
Published: December 2003

Natural products have been synthesized for billions of years in animals, plants, and microorganisms. As a rule they occur enantiomerically pure. Their chiral character corroborates their use in metabolism or as biologically active agents. Natural products may be insufficient in quality or quantity. They have recently begun to become accessible, either unchanged or modified, by biological synthesis; here, too, they are obtained enantiomerically pure. In the last twenty years chemical synthesis has become a major concern of organic chemists. Their target compounds are primarily enantiomerically pure natural products or biologically active variants thereof.
Synthesis of the Chiral Synthetic Building Block (1R, 5S)‐3‐Phenyl‐4‐oxa‐2,6‐diazabicyclo[3.2.0]hept‐2‐en‐7‐one from 6‐Aminopenicillanic Acid
Authors: Häbich Dieter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1035. DOI:10.1002/anie.198310350
The Photooxygenation of Estrogens: a New Synthesis of 19‐Norsteroids
Authors: Lupón Pilar , Gómez José , Bonet Juan‐Julio
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1025. DOI:10.1002/anie.198310250
Photochemistry of Previtamin D3 at 92 K; Formation of an Unstable Tachysterol3 Rotamer
Authors: Maessen Paul A. , Jacobs Harry J. C. , Cornelisse Jan , Havinga Egbert
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 994. DOI:10.1002/anie.198309940
Synthesis and Structure of a Linearly anti‐Annelated Tetracycloundecane. A Potential Precussor for a Coriolin Synthesis
Authors: Demuth Martin , Cánovas Antonio , Weigt Eva , Krüger Carl , Tsay Yi‐Hung
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1053. DOI:10.1002/anie.198310530
Preparation and Properties of Tetrabenzoporphyrinatoiron(II) and Its Isocyanide Complexes
Authors: Fischer Konrad , Hanack Michael
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1017. DOI:10.1002/anie.198310170
Reversal of the Refioselectivity in the Zirconocene‐induced Coupling of a ketone with Isoprene
Authors: Erker Gerhard , Dorf Ulrich
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1120. DOI:10.1002/anie.198311200
Diels‐Alder Reactions of Dienes with Alkynes Catalyzed by Diazadieneiron
Authors: tom Dieck Heindirk , Diercks Reiner
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1138. DOI:10.1002/anie.198311380
Thermolysis and Reactions of 4,5‐Benzotricyclo[4.1.0.01,3]hept‐4‐ene and o‐(Propadienyl)styrene
Authors: Brinker Udo H. , Wilk Gabriele , Gomann Klaus
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1228. DOI:10.1002/anie.198312280
SbF2+ as a Lewis Acid in Na(SbF)PO4·nH2O (n = 2–4) and NH4(SbF)PO4·H2O
Authors: Mattes Rainer , Holz Klaus
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1315. DOI:10.1002/anie.198313150
First Proof of di‐, tri‐, and all‐cis‐Conformations in Sterically Hindered Trimethinecyanines (Carbocyanines) of the Indoline and Benzothiazole Series
Authors: Allmann Rudolf , Anis Hans‐Joachim , Benn Reinhard , Grahn Walter , Olejnek Stanislaw , Waśkowska Alicja
Published: December 2003

The complete manuscript of this communication appears in:Angew. Chem. Suppl. 1983, 1147. DOI:10.1002/anie.198311470
Naked Phosphorus Atoms as Trigonally Planar Coordinated Bridge Ligands
Authors: Lang Heinrich , Zsolnai Laszlo , Huttner Gottfried
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1451. DOI:10.1002/anie.198314510
Diphosphorus, :PP:, as Eight‐Electron Ligand
Authors: Lang Heinrich , Zsolnai Laszlo , Huttner Gottfried
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1463. DOI:10.1002/anie.198314630
Synthesis and Structure of a Macrocycle with a Skeletal Framework of Arsenic, Carbon, Oxygen, and Nitrogen Atoms
Authors: Roesky Herbert W. , Djarrah Habibollah , Lucas Joachim , Noltemeyer Mathias , Sheldrick George M.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1424. DOI:10.1002/anie.198314240
Alkyne Complexes of Tungsten(IV)
Authors: Theopold Klaus H. , Holmes Steven J. , Schrock Richard R.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1409. DOI:10.1002/anie.198314090
Stable Olefin Complexes of Pt(II) Containing Trichlorostannate(II) Ligands: Structure of [Ph4As][Pt(SnCl3)3(1,5‐cod)]
Authors: Albinati Alberto , Pregosin Paul S. , Rüegger Heinz
Published: December 2003

Fivefold coordinated platinum(II) is contained in the novel complex 1. It is the first square‐pyramidal platinum‐tin complex; one of the three Sn atoms adops the axial position. 1 has a dynamic structure in solution.
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Novel Clusters of Cobalt and Nickel with Organophosphorus Ligands
Authors: Fenske Dieter , Basoglu Ramazan , Hachgenei Johannes , Rogel Friedhelm
Published: December 2003

A surprisingly easy access to the preparation of transition‐metal clusters is the reaction of MCl2 (M  Co, Ni) with PhP(SiMe3)2 and PPh3. In this way [Co4(μ3‐PPh)4(PPh3)4] and [Ni8(X)4(μ4‐PPh)6(PPh3)4] (XCl and CO) can be isolated. The paramagnetic complex with X  Cl contains 116 valence electrons and can be considered as a mixed‐valence cluster of Ni0 and Ni1+.
Biochemical Aspects of Cholinergic Excitation
Authors: Maelicke Alfred
Published: December 2003

A prerequisite for every biological system to develop and to continue to function (“to live”) is an effective communication between its components, i.e. its cells. This intercellular communication is essentially of a chemical nature: It employs neurotransmitters and hormones as messengers, and receptors as the receivers of transmitted signals. As is typical for all communication systems, biological signal processes usually also utilize only relatively small amounts of material. This general rule, however, does not apply to some synaptic communication systems. One typical exception, for instance, is the nerve‐muscle synapse and, in particular, its special form, the nerve‐electroplaque synapse of electric fish. These systems, therefore, lend themselves to biochemical studies permitting investigation of the molecular basis of biological communication processes. Thus, the acetylcholine receptor of the plasma membrane of the postsynaptic cell was established as a structurally and functionally rather complicated “transducer system” responsible for both the reception of the chemical message and its conversion into an electrical activity of the receiving cell.
15N‐15N Coupling Constants and Rotational Barriers of Nitrosamines
Authors: Bandmann Heinz , Heymanns Peter , Siem Carola , Rademacher Paul
Published: December 2003

The double bond character of the NN bond in secondary nitrosamines can be measured from the15N15N coupling constants in 15N‐Labeled model compounds: In the examples selected the coupling constants, the degree of π‐bonding, and the calculated ΔH* value of the internal rotation are linearly correlated.
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[Mo4(μ3‐S)4(μ‐S2CNEt2)2(S2CNEt2)4], a Compound Containing a Cubane‐Like Mo4S4 Cluster
Authors: Mak Thomas C. W. , Jasim Khalid S. , Chieh Chung
Published: December 2003

An Mo4 tetrahedron as part of a readily distorted Mo4S4 cube is observed in the title compound (black crystals). In this complex, molybdenum is coordinated only by sulfur. Four of the six dithiocarbamate ligands are each bound to an Mo atom; the two remaining ligands each bridge an MoMo bond.
The Allyloxycarbonyl (Aloc) Moiety—Conversion of an Unsuitable into a Valuable Amino Protecting Group for Peptide Synthesis
Authors: Kunz Horst , Unverzagt Carlo
Published: December 2003

A novel method for the cleavage of the Aloc protecting group (Aloc = allyloxycarbonyl) permits the effective and selective synthesis of sensitive peptide derivatives, e.g. with serine residues. The protecting group can be removed from peptide esters such as Aloc‐Phe‐Ser(tBu)‐OtBu via catalytic allyl transfer with [Pd(PPh3)4] to dimendone; the tBu groups are retained. In contrast, with CF3COOH only the tBu groups are removed from the Aloc‐tBu esters.
Peptide Structures of the Alamethicin Sequence: The C‐Terminal α/310 Helical Nonapeptide and Two Pentapeptides with Opposite 310 Helicity
Authors: Bosch Roland , Jung Günther , Schmitt Heribert , Sheldrik George M. , Winter Werner
Published: December 2003

A natural oligopeptide with α‐aminoisobutyric acid residues (Aib), which reduce the conformation space, is alamethicin. This icosapeptide antibiotic, as an ionophoric, membrane pore former, is a model compound for the excitability of nerve membranes. Interesting helical structures have now been discovered in the synthetic segments of such compounds: thus, 2 forms a right‐handed 310 helix; in contrast, 1 forms a left‐handed 310 helix! Previously, only one other 3 helix was known.
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