bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular modeling of saccharides, 7. The conformation of sucrose in water: A molecular dynamics approach
Authors: Immel Stefan , Lichtenthaler Frieder W. 
Published: July 2007

AbstractA molecular mechanics analysis of the conformational properties of sucrose in vacuo in terms of the intersaccharidic torsion angles Φ and Ψ, revealed three energy minima. The geometry of the global minimum‐energy closely resembles the solid‐state structure. Most notably, the interresidue hydrogen bonding interaction 2g‐O…︁HO‐1f present in the crystal, is retained under vacuum boundary conditions, indicating the molecular geometries adopted in the crystal lattice and in vacuo to be similar. For aqueous solutions, detailed molecular dynamics simulations of sucrose „soaked”︁ with 571 water molecules in a periodic box (truncated octahedron), revealed this direct H‐bond interaction to be replaced by an indirect, water‐mentioned one: an interresidue water‐bridge of the 2g‐O…︁H2O…︁HO‐1f type prevailed with a high significance and a long life‐time. This means the linkage geometry of sucrose in water–despite the absence of direct interresidue hydrogen bonds–again closely resembles the solid‐state and in vacuo geometry in terms of the orientation of the glucose and the fructose unit relative to one another. The solution dynamics of, and the hydration around sucrose were analyzed in terms of pair distribution functions. These indicate strong hydrogen bonding between all sucrose hydroxyls (as donors and acceptors) and water within a first, well‐defined hydration layer (hydroxyl‐oxygen–water distances 1.8–3.5 Å), whereas the acetalic oxygens are engaged to a lesser extent as H‐bond acceptors. The second hydration shell (>4 Å) is rather diffuse and less pronounced, indicating those water molecules to be in a disordered state. The implications of the hydration shell and the water bridge on the crystallization process of sucrose and on binding towards transporter proteins, and the sweet‐taste receptor, are discussed. Other sucrose conformations that may conceivably exist in aqueous solution, may have eluded the MD simulation search. The umbrella sampling technique was applied for establishing the free energy profile as a function of the intersaccharidic torsion angles. The resulting concise picture of the dynamics of sucrose in aqueous solution, encompassing the entire conformational space available, revealed only two energy minima. Of these, the by far, most populated global minimum structure corresponded to the most stable solution geometry, as found by molecular dynamics.
Utilization of industrial waste materials, 5. Synthesis of new, chiral 1,3,2‐oxazaphospholidine‐borane complexes and attempts to apply them in the stereoselective synthesis
Authors: Peper Viola , Stingl Klaus , Thümler Hajo , Saak Wolfgang , Haase Detlev , Pohl Siegfried , Jugé Sylvain , Martens Jürgen 
Published: July 2007

AbstractNew, chiral 1,3,2‐oxazaphospholidine‐borane complexes 3a‐b and 8a‐d were synthesized from the β‐amino alcohols 1a‐b and 6a‐d. The borane complexes 3, 8a, 8c, and 8d were allowed to react with different organolithium compounds and afforded the corresponding aminophosphane‐borane complexes 4a–c and 9a‐g. Acid methanolysis of those complexes led to the formation of the phosphinite‐borane complexes 5a‐c. This is a further example of the utilization of the industrial waste material (all‐R)‐2‐azabicyclo‐[3.3.0]octane‐3‐carboxylic acid. The catalytic efficiency of the chiral 1,3,2‐oxazaphospholidine‐borane complexes 3a, 3b, and 8c was examined in the enantioselective borane reduction of some ketones.
Synthesis of Vinylallenes by Conjugate 1,6‐, 1,8‐, 1,10‐ and 1,12‐Addition Reactions of Organocuprates with Acetylenic Michael Acceptors and Their Use as Dienes in Intermolecular Diels‐Alder Reactions
Authors: Koop Ulrich , Handke Gabriele , Krause Norbert 
Published: July 2007

AbstractVarious vinylallenes were synthesized by conjugate cuprate additions to acetylenic Michael acceptors. Thus, 1,6‐addition reactions with 2‐en‐4‐ynoates 1, 3, and 5a, respectively, furnished vinylallenes 2, 4, and 7 after regioselective electrophilic capture of the allenyl enolates formed. Likewise, 1,8‐addition to 2,4‐dien‐6‐ynoates 8a and 10 gave the vinylallenes 9 and 11, whereas the 1,10‐addition of Me2CuLi to 2,4,6‐trien‐8‐ynoate 12 provided allene 13, and the analogous 1,12‐addition to 2,4,6,8‐tetraen‐10‐ynoate 14 furnished the polyene 15. These vinylallenes are valuable dienophiles in regio‐ and stereoselective Diels‐Alder reactions, as evidenced by the formation of the cycloaddition products 16–24. In the presence of Lewis acids, vinylallene 4a presumably rearranges to a cyclopentadiene derivative which then forms the cycloadducts 25 and 26.
New Efficient, Flexible and Regioselective Synthesis of 2,4‐Di‐ and 2,3,4‐Trialkylated an Arylated 1H‐Pyrroles
Authors: Enders Dieter , Maaßen Ralf , Han Sin‐Ho 
Published: July 2007

AbstractStarting from easily available 2‐acetoxy aldehyde dimethylhydrazones rac‐2, we prepared various alkyl‐ and aryl‐substituted 1H‐pyrroles 6 in good overall yield. The titariummediated a2‐umpolung reaction of rac‐2 with different acyclic and cyclic silyl enol ethers 3 leads directly or via 4‐oxo hydrazones rac,anti‐4 to 1‐(dimethylamino)‐1H‐pyrroles 5. A novel method for the reductive removal of the dimethylamino group affording 1H‐pyrroles 6 is presented.
Pyrrolo‐ and Thiophenoperylenedicarboximides – Highly Fluorescent Heterocycles
Authors: Langhals Heinz , Feiler Leonhard 
Published: July 2007

AbstractPyrrolo‐ and thiophenoperylenedicarboximides 4 and 7 were prepared by reductive cyclization of 1‐nitroperylenedicarboximides 3 and 5 with phosphorous acid esters and sulfur, respectively. The imides 4 and 7 are highly fluorescent and are easily monofunctionalized by nucleophilic substitution reactions which makes them useful for fluorescent labeling.
Prearranged Glycosides, 4!. Synthesis via Prearranged Glycosides of a Tetrasaccharide Fragment Related to the Capsular Polysaccharide of Streptococcus pneumoniae Type 27
Authors: Schüle Gunter , Ziegler Thomas 
Published: July 2007

AbstractThe blockwise synthesis of the pyruvated tetrasaccharide 4,6‐(S)‐pyruvic‐acetal‐β‐d‐GlcNAcp‐(1→3)‐α‐d‐Galp‐(1→4)‐β‐l‐Rhap‐(1→4)‐β‐d‐Glcp‐O(CH2)5NH2 (32), related to the repeating unit of the capsular polysaccharide of Streptoccus pneumoniae type 27, by coupling of the suitably protected disaccharide blocks 4,6(S)‐pyruvic‐acetal‐β‐d‐GlcNAcp‐(1→3)‐α‐d‐Galp‐trichloroacetimidate (13) and β‐l‐Rhap‐(1→4)‐β‐d‐Glcp‐O(CH2)5NHZ (29β) is described. The latter disaccharide acceptor was prepared via prearranged glycosides by intramolecular glycosylation of a protected 5‐aminopentyl β‐d‐glucopyranoside linked by a succinyl bridge at C‐3 to C‐2 of ethyl 1‐thio‐α‐l‐rhamnopyranoside. The dependence of the anomeric selectivity of the coupling on the nature of the protecting group at C‐4 of the rhamnosyl moiety is studied.
[3 + 2] Cycloadditions of Nitrile Oxides to C70 Affording 4,5‐Dihydroisoxazoles and Their Structure Determination
Authors: Irngartinger Hermann , Köhler Claus‐Markus , Baum Gerhard , Fenske Dieter 
Published: July 2007

AbstractThree isomeric monoadducts 2aA, 2aB, and 2aC of fullerene‐70 with 2,4,6‐trimethoxybenzonitrile oxide 1a were synthesized and isolated. With a combination of FAB‐MS, 13C‐ and 1H‐NMR spectroscopy the structure of the orientational and regioisomers could be assigned. A precise X‐ray structure analysis of the isomer 2aA with the substituent placed above the pole could be performed at low temperature (170 K). The corresponding monoadduct 3a of C60 was synthesized, isolated and characterized. In the same manner a mixture of three isomeric monoadducts 2b of C70 with ethoxycarbonylnitrile oxide 1b was obtained and characterized. The monadducts 2c of C70 with 9‐anthrylnitrile oxide 1c were characterized by FAB‐MS.
Synthesis of New Nepenthone Derivatives
Authors: Marton János , Szabó Zoltán , Simon Csaba , Hosztafi Sándor , Makleit Sándor 
Published: July 2007

AbstractHydrogenation of nepenthone (3a) leads to a mixture of dihydronepenthone (3c) and the secondary alcohol (20S)‐4b. The enantiomeric secondary alcohol (20S)‐4b is prepared from the 7α‐formyl‐6,14‐ethenomorphinan derivative 3b by reaction with phenylmagnesium bromide to afford a mixture of the diastereoisomeric alcohols 4a. Hydrogenation of 4a leads to (20S)‐4b and (20R)‐4b, which are separated by fractional crystallization. The conformations of (20S)‐4b and (20R)‐4b are determined by NOE difference experiments.
Synthesis and Properties of 2‐Carboxyalkyl‐1,2‐benzisoselenazol‐3(2H)‐ones and Related Organoselenium Compounds as Nitric Oxide Synthase Inhibitors and Cytokine Inducers
Authors: Mlochowski Jacek , Juchniewicz Leszek , Kloc Krystian , Gryglewski Ryszard J. , Jakubowski Andrzej , Inglot Anna D. 
Published: July 2007

AbstractA convenient synthesis of the 2‐carboxyalkyl‐1,2‐benzisoselenazol‐3(2H)‐ones 4a–k and their esters 41–p from 2‐(chloroseleno)benzoyl chloride (2) and amino acids or their carboxy esters is reported. In similar way other 2‐substituted 1,2‐benzisoselenazol‐3(2H)‐ones 4q–u were synthesized. The related bis[2‐(carbamoyl)phenyl] diselenides 5 were obtained by reductive conversion of 1,2‐benzisoselenazol‐3(2H)‐ones 4 or directly by the reaction of bis[2‐(chlorocarbonyl)phenyl] diselenide (3) with compounds having a primary amino group. It was found that some of compounds 4 and 5 are modest cytokine (TNF, IFN) inducers in human peripheral blood leucocyte cultures and block the constitutive endothelial nitric oxide synthase (ce NOS).
A Generalized Solvent Basicity Scale: The Solvatochromism of 5‐Nitroindoline and Its Homomorph 1‐Methyl‐5‐nitroindoline
Authors: Catalán Javier , Díaz Cristina , López Vicenta , Pérez Pilar , De Paz José‐Luis G. , Rodríguez José Gonzalo 
Published: July 2007

AbstractA total of 202 organic solvents and the gas phase were placed on a solvent basicity scale for hydrogen bond acceptor based on parameter SB. The value of such a parameter can readily be determined from the UV/Vis spectrum for an appropriate acid probe (5‐nitroindoline) (NI) and its non‐acid homomorph (1‐methyl‐5‐nitroindoline) (MNI). The proposed scale can advantageously substitute the more widely used solvent scales such as Gutmann's donor number (DN), the Koppel‐Palm B(MeOD) scale, and the Taft‐Kamlet β scale. While data for the proposed scale are derived only from electronic transitions, they are accurately descriptive of solvent basicity in both spectroscopy (UV/Vis, IR and NMR) and miscellaneous chemical areas (thermodynamic, kinetics, and electrochemistry).
Dyotrope Wasserstoffübertragung in Dihydrosesqui‐ und in Dihydro‐syn‐sesterbicyclo[2.2.2]octenen
Authors: Grimme Wolfram , Pohl Kathrin , Wortmann Jens , Frowein Dirk 
Published: July 2007

Dyotropic Hydrogen Transfer in Dihydrosesqui‐ and in Dihydro‐syn‐sesterbicyclo[2.2.2]octenesThe intramolecular dyotropic hydrogen transfer is studied in dihydrosesquibicyclo[2.2.2]octenes. In the parent system 4‐d2 the process transfers two hydrogen atoms from the ethano to the etheno bridge; it is thermoneutral and reversible at 200°C, In 12a, b a 1,2‐dihydrobenzene acts as the hydrogen donor; the reaction is highly exothermic and occurs already at room temperature. In 19‐d4 the dyotropic hydrogen exchange from a 1,2‐dihydrobenzene to benzene is again thermoneutral and occurs at 200°C. The kinetic parameters of these reactions, listed in Table 7, indicate a concerted pericyclic pathway. In the extended dihydro‐syn‐sesterbicyclo[2.2.2]octenes 6‐d2 and 15a, b two hydrogen transfers occur in sequence, the central bridge serving as a relais. Here the dyotropic processes establish equilibria between structures with stacked and isolated double bonds, allowing an evaluation of the van der Waals interaction in the former. It is found that this interaction changes with the type of the stakked π‐systems from repulsive in 6‐d2 to slightly attractive in 16a (see Table 8).
Synthesis of Medium and Large Ring Compounds, XLIII. Synthesis and Isomerization of 8,9‐Dimethyl[6]paracyclophane and Its Bridged Dewar Isomer
Authors: Tochtermann Werner , Rodefeld Lars , Dreeskamp Herbert , Sarge Stefan M. 
Published: July 2007

AbstractAn improved sonochemical procedure for the synthesis of dimethyl [6]paracyclophane‐8,9‐dicarboxylate (2a) on a 10‐g scale is described. The title compound 2d was synthesized from 2a in three steps. Irradiation of 2d yielded the Dewar isomer 3. In solution, the reaction enthalpy for the thermal isomerization of 3 to 2d was determined to be ‐162 ± 16 kJ · mol‐1, while the activation energy for this reaction was found to be 123 ± 12 kJ · mol‐1.
First Synthesis of Enantiomerically Pure Primary Helical Spirocycles Based on the Repetitive Addition of Lithiated Methoxyallene to Chiral 3(2H)‐Dihydrofuranone Derivatives
Authors: Hormuth Stephan , Schade Wolfgang , Reißig Hans‐Ulrich 
Published: July 2007

AbstractRepetitive additions to chiral 3(2H)‐Dihydrofuranones opened a route to the first enantiomerically pure primary helical spirocyclic compounds. Thus, addition of lithiated methoxyallene 2 to furanone 9 provided adduct 10 with excellent diastereoselectivity. Cyclization with potassium tert‐butoxide in DMSO followed by acid hydrolysis of the resulting enol ether moiety gave spirocyclic furanone 12 in very good overall yield. Repetition of this three‐step sequence converted 12 into 15. For the next series of reactions cerium compound 16 instead of 2 was employed as nucleophile which resulted in reasonable conversion of 15 into adduct 17. By application of the usual methods this compound was transformed into the enantiomerically pure tetracyclic spiro compound 19 in moderate overall yield. Functionalized spiro compounds as described in this paper may serve as enantiomerically pure building blocks in supramolecular chemistry.
Acetogenic Isoquinoline Alkaloids, LXXXII. Biomimetic Total Synthesis of Michellamines A–C
Authors: Bringmann Gerhard , Götz Roland , Harmsen Sven , Holenz Jörg , Walter Rainer 
Published: July 2007

AbstractThe biomimetic first total synthesis of michellamines A, B, and C (1a–c), naturally occurring quateraryl alkaloids with high anti‐HIV activity, is described. Key precursors are the molecular “halves” of michellamines, the antimalarial naphthylisoquinoline alkaloids korupensamine A (2a) and B (2b), which are likewise natural products. These “monomeric” naphthylisoquinoline alkaloids were prepared by Stille‐type intermolecular aryl coupling of the O‐isopropyl‐protected and trialkylstannyl‐activated naphthalene building block 4b with the threefold benzyl‐protected and brominated, enantiomerically pure tetrahydroisoquinoline building block 3a. Ultimate “dimerization” of the protected korupensamines was achieved by biomimetic oxidative phenolic coupling using silver(I) oxide, followed by deprotection to give authentic michellamines. This synthetic route should allow us to easily prepare a broad series of modified analogs of michellamines for extensive structure‐activity investigations.
New Facts on the Stereoselectivity of Monobromocarbenoid Additions to Cyclic Alkenes
Authors: Dehmlow Eckehard V. , Lustinetz Horst 
Published: July 2007

AbstractThe monobromocarbenoid derived from CH2Br2 and NaN(SiMe3)2 gives only endo adducts 4, 5, and 6 with 1,5‐cyclooctadiene, but shows no selectivity with 1,3‐cyclooctadiene. A literature report of a high endo adduct preference of cyclooctene cannot be duplicated, but cyclodecene is converted to 3 with 100% selectivity. Bromocarbenoid adducts 11, 13, and 14 of norbornene and norbornadiene are reported. A possible explanation for the varying selectivities is given.
Solid State and Solution Structures of O‐Alkyl‐ and of O‐Acyl Derivatives of 1‐Hydroxypyridine‐2(1H)‐thione
Authors: Hartung Jens , Hiller Margit , Schwarz Michaela , Svoboda Ingrid , Fuess Hartmut 
Published: July 2007

AbstractAlthough Barton's radical precursors, the O‐acyl derivatives of 1‐hydroxypyridine‐2(1H)‐thione 2, have been studied in detail for more than a decade, to date nothing has been reported on the solid state or the solution geometries of these molecules or the analogous oxo derivatives, the pyridones 7, 8. In view of this, selected O‐alkyl and O‐acyl derivatives of pyridinethiones and of 2‐(1H)pyridones have been prepared and investigated by X‐ray diffraction and NMR (COSY, NOE) experiments. The X‐ray data indicate alternating bond lengths in the carbon framework of the heterocycles 2d, 3b, 7b, and 8 and long NO bonds [1.394(4)–1.398(2) Å]. In all the compounds studied, the O‐alkyl and the O‐acyl groups are twisted out of the plane of the heterocycles, which is in accord with the VSEPR concept. Further, the thermal stabilities of thiohydroxamic acid derivatives 2, 3 and of substituted pyridones 7, 8 were studied by differential scanning calorimetry (DSC).
Resonanzenergie von Diradikalen — 1,8‐Naphthoquinodimethan
Authors: Roth Wolfgang R. , Unger Christian , Wasser Thorsten 
Published: July 2007

Resonance Energy of Diradicals. — 1,8‐NaphthoquinodimethaneFrom the racemization of 19c and the temperature and NO dependence of the trapping rate of 20b between 218 and 288°C the energy profile for the equilibrium 19b ⇄ 20b is derived. The singlet‐triplet splitting of the diradical is 2.5 kcal · mol‐1 with the triplet being the ground state. By comparison of the experimental reaction enthalpy with the analogous value for 25, 26 or a hypothetical model reaction with non‐interacting radicals it is shown that the stabilizing interaction of the radicals in the singlet state of 20b is negligible making the stabilization of the triplet equivalent to the singlet‐triplet splitting. By using literature data it is shown by an analogous analysis that the interaction of the radicals in the bisallyl diradical 28 and in the triplet state of the trimethylenmethane derivative 29 is also negligible whereas in the singlet state of 29 the interaction is strongly destabilizing.
Wechselwirkungen in Molekülkristallen, 111. Kristallzüchtung und Strukturbestimmung von Donator/Akzeptor‐Komplexen aus 1,2,4,5‐Tetrakis(alkylthio)benzolen und Brom oder Iod
Authors: Bock Hans , Rauschenbach Andreas , Näther Christian , Kleine Markus , Havlas Zdenek 
Published: July 2007

Interactions in Crystals, 111Part 110: Ref.[1].

. —
Crystallization and Structure Determination of Donor/Acceptor Complexes between 1,2,4,5‐Tetrakis(alkylthio)benzene Derivatives and Bromine or Iodine
Based on preceding cyclovoltammetric and UV/Vis measurements, red crystals of the donor/acceptor complex {1,2,4,5‐tetrakis(ethylthio)benzene…(Br2)2} are grown by using Br2 gasphase diffusion into a CCl4 solution of 1,2,4,5‐tetrakis(ethylthio)benzene. In addition, the corresponding iodine complex {1,2,4,5‐tetrakis(isopropylthio)benzene ⃛(I2)3} is crystallized. The structure determinations prove for the I2 adduct an interesting packing motif, in which two crystallographically independent I2 acceptors bridge each four sulfur donors. The Br2 adduct shows a three‐dimensional network with subunits >S ⃛BrBr ⃛S<, in which the BrBr bond is surprisingly elongated by 13 pm (!) relative to the gasphase electron diffraction value for bromine. — The structure discussion is based on iodine acceptor complexes listed in the Cambridge Structural Database and reveals angular‐dependent iodine coordination vectors to sulfur as well as a correlation between II bond lengths and contact distances S ⃛I. Density functional calculations for the model system (H3C)2S ⃛BrBr ⃛S(CH3)2 with the experimentally determined structural parameters suggest that a charge of ‐0.25 is transferred to the BrBr acceptor molecule, which allows to rationalize its 13‐pm elongation on complexation to {1,2,4,5‐tetrakis(ethylthio)benzene ⃛(Br2)2}.
Antibiotics from Gliding Bacteria, LXXIX. – Chemical Modification of the Antifungal Macrolide Soraphen A1α: Deoxygenation in the South‐East Ring Segment
Authors: Kiffe Michael , Schummer Dietmar , Höfle Gerhard 
Published: July 2007

AbstractThe present paper describes the chemical modification of the antifungal macrolide soraphen A1α (1) by selective removal of oxygen substituents in the south‐east ring segment. In the course of this investigation two key derivatives were prepared: 4‐demethyl‐5‐O‐(4‐methoxybenzyl)‐4‐episoraphen (6) and 3,5‐dideoxy‐4‐oxosoraphen (22). 6 served as precursor for 4‐demethoxysoraphen (19) and 4‐demethoxy‐5‐deoxysoraphen (20). 22 was used for the deoxygenation in positions C‐3, C‐4 and C‐5 and for the synthesis of 3,5‐didesoxysoraphen (24) as well as 4‐demethoxy‐3,5‐dideoxysoraphen (27). The comparison of the antifungicidal activity of these derivatives showed that the OH group in position C‐3 is essential for the biological activity of the soraphens.
A Biphenyl Construction Kit for Modular Chemistry
Authors: Hensel Volker , Schlüter A.‐Dieter 
Published: July 2007

AbstractThe synthesis of a number of telechelic biphenyls with one of the functional groups, B(OH)2, TMS, Br and I, at each ring is presented. These biphenyls constitute a construction kit for modular chemistry using the Suzuki cross‐coupling protocol.
Synthesis of Methyl Derivatives of 4H‐Furo[2,3‐h]quinolin‐4‐one and 5H‐Furo[3,2‐g]quinolin‐5‐one
Authors: Rao Vadapalli S. , Rodighiero Paolo , Chilin Adriana , Castellin Andrea , Manzini Paolo , Guiotto Adriano 
Published: July 2007

AbstractSynthesis of the linear and angular furoquinolin‐4‐one derivatives 6 and 12 was performed, using nitrobenzofurans 3 and 9 as key intermediates. These compounds were reduced to the corresponding aminobenzofurans 4 and 10, which were condensed in two steps to yield, the linear furoquinolin‐4‐ones 6a,b and the angular ones 12a,b.
No Evidence for Intramolecular Hydrogen Bonds in α‐Fluorocarboxamides
Authors: Michel Dominique , Witschard Martin , Schlosser Manfred 
Published: July 2007

Abstractα‐Fluorocarboxamides 3a–3e can be prepared by treatment of the corresponding α‐hydroxycarboxamides with diethylaminosulfur trifluoride. The infrared spectra argue strongly against the existence of intramolecular hydrogen bonds between the amino group and the fluorine atom.
Combinatorial Libraries: Studies in Molecular Recognition and the Quest for New Catalysts
Authors: Gennari Cesare , Nestler H. Peter , Piarulli Umberto , Salom Barbara 
Published: July 2007

AbstractCombinatorial libraries offer a new powerful tool for gathering empirical information about host/guest interactions and for developing catalysts for organic reactions. Combinatorial approaches to molecular recognition are discussed, i.e. screening of libraries of ligands with synthetic receptors and libraries of synthetic receptors with the ligands for which selective binding is desired. Recent achievements in the development of new catalysts for organic synthesis using combinatorial approaches are also reviewed.
Diastereo‐ and Enantioselective Synthesis of Carbocyclic and Heterocyclic β‐Amino Acids by Tandem Aza Michael Addition/Intramolecular Cyclization
Authors: Enders Dieter , Wiedemann Jürgen 
Published: July 2007

AbstractThe stereoselective conjugate addition of (S)‐(–)‐1‐(trimethylsilylamino)‐2‐(methoxymethyl)pyrrolidine (TMS‐SAMP) to ω‐halide‐substituted α,β‐unsaturated esters 1 is utilized to prepare carbocyclic and heterocyclic β‐amino acids 2 and 5 of high diastereo‐ and enantiomeric purity via the corresponding β‐hydrazino esters by selective intramolecular alkylation of the intermediate ester enolate or the hydrazino moiety. The auxiliary is removed by reductive NN bond cleavage. The stereochemistry of the resulting trans‐2‐aminocycloalkanecarboxylic acids (2) and azacycloalk‐2‐ylacetic acid esters (5) is confirmed by NMR spectroscopy and polarimetry. A transition‐state model for the highly diastereoselective conjugate addition of TMS‐SAMP to enoates is presented.