bluuebunny/crossref_metadata_2025_split huggingface dataset:
8‐Aza‐2′‐deoxyguanosine and Related 1,2,3‐Triazolo[4,5‐d]pyrimidine 2′‐Deoxyribofuranosides
Authors: Seela Frank , Lampe Sigrid 
Published: December 2004

AbstractThe synthesis of 8‐azaguanine N9‐, N8‐, and N7‐(2′‐deoxyribonucleosides) 1–3, related to 2′‐deoxyguanosine (4), is described. Glycosylation of the anion of 5‐amino‐7‐methoxy‐3H‐1,2,3‐triazolo[4,5‐d]pyrimidine (5) with 2‐deoxy‐3,5‐di‐O‐(4‐toluoyl)‐α‐D‐erythro‐pentofuranosyl chloride (6) afforded the regioisomeric glycosylation products 7a/7b, 8a/8b, and 9 (Scheme 1) which were detoluoylated to give 10a, 10b, 11a, 11b, and 12a. The anomeric configuration as well as the position of glycosylation were determined by combination of UV, 13C‐NMR, and 1H‐NMR NOE‐difference spectroscopy. The 2‐amino‐8‐aza‐2′‐deoxyadenosine (13), obtained from 7a, was deaminated by adenosine deaminase to yield 8‐aza‐2′‐deoxyguanosine (1), whereas the N7‐ and N8‐regioisomers were no substrates of the enzyme. The N‐glycosylic bond of compound 1 (0.1 N HCl) is ca. 10 times more stable than that of 2′‐deoxyguanosine (4).
1‐(2′‐Deoxy‐β‐D‐xylofuranosyl)cytosine: Base pairing of oligonucleotides with a configurationally altered sugar‐phosphate backbone
Authors: Seela Frank , Wörner Karlheinz , Rosemeyer Helmut 
Published: December 2004

AbstractSolid‐phase synthesis of the oligo(2′‐deoxynucleotides) 19 and 20 containing 2′‐deoxy‐β‐D‐xylocytidine (4) is described. For this purpose, 1‐(2‐deoxy‐β‐D‐threo‐pentofuranosyl)cytosine ( = 1‐(2‐deoxy‐β‐D‐xylofuranosyl)‐cytosine; 4) was protected at its 4‐NH2 group with a benzoyl (→ 5) or an isobutyryl (→8) residue, and a dimethoxytrityl group was introduced at 5′‐OH (→ 7, 10; Scheme 2). Compounds 7 and 10 were converted into the 3′‐phosphonates 11a,b. While 19 could be hybridized with 21 and 22 under formation of duplexes with a two‐nucleotide overhang on both termini (19 · 21: Tm 29°; 19 · 22: Tm 22°), the decamer 20 bearing four xCd residues could no longer be hybridized with one of the opposite strands. Moreover, the oligonucleotides d[(xC)8C] (13), d[(xC)4C] (14), d[C(xC)4C] (15), and d[C(xC)3C] (16) were synthesized. While 13 exhibits an almost inverted CD spectrum compared to d(C9) (17), the other oligonucleotides show CD spectra typical for regular right‐handed single helices. At pH 5, d[(xC)8C] forms a stable hemi‐protonated duplex which exhibits a Tm of 60° (d[(CH+)9] · d(C9): Tm 36°). The thermodynamic parameters of duplex formation of (13H+ · 13) and (17H+ · 17) were calculated from their melting profiles and were found to be identical in ΔH but differ in ΔS (13H+ · 13: ΔS = −287 cal/K mol; 17H+ · 17: ΔS = −172 cal/K mol).
Nucleotides. Part XLIII. Solid‐phase synthesis of oligoribonucleotides using the 2‐dansylethoxycarbonyl (  2‐{[5‐(dimethylamino)naphthalen‐1‐yl]sulfonyl}ethoxycarbonyl; dnseoc) group for 5′‐hydroxy protection
Authors: Bergmann Frank , Pfleiderer Wolfgang 
Published: December 2004

AbstractA new efficient method for solid‐phase synthesis of oligoribonucleotides via the phosphoramidite approach is described. The combination of the base‐labile 2‐dansylethoxycarbonyl (Dnseoc) group for 5′‐OH protection with the acid‐labile tetrahydro‐4‐methoxy‐2H‐pyran‐4‐yl (Thmp) group as 2′‐OH blocking group is orthogonal regarding cleavage reactions and fulfills the requirements of an automated synthesis in an excellent manner if the phosphoramidite function carries the N,N‐diethyl‐O‐[2‐(4‐nitrophenyl)ethyl] substitution.
Mixed Azines of Naloxone with Dihydromorphinone Derivatives
Authors: Schmidhammer Helmut , Kaspar Felizia , Marki Arpad , Borsodi Anna 
Published: December 2004

AbstractThe mixed azines 4 and 5 were prepared by reaction of naloxazone (2) with either oxymorphone (6) or 14‐O‐methyloxymorphone (7) and tested in vitro using opioid receptor binding assays and in vivo using the AcOH‐writhing test in mice. Compound 4 was found to be a partial agonist, while compound 5 was a potent opioid agonist with higher potency than morphine.
Synthesen mit Übergangsmetall‐Komplexen. Teil 2. Neue Fluoranthen‐Derivate mit (1,6‐Methano[10]annulen‐2‐yl)‐ und/oder (Naphthalin‐1‐yl)‐Substituenten
Authors: Neidlein Richard , Kux Ulrich 
Published: December 2004

Syntheses with Transition‐Metal Complexes. New Fluoranthene Derivatives with 1,6‐Methano[10]annulen‐2‐yl and/or Naphthalen‐1‐yl SubstituentsIn the course of investigations of molecules bearing ‘parallel triple bonds’, the fluoranthene derivatives 6–10 were synthesized by reaction of the ‘rhodacycle’ 4 with selected alkynes. The spectroscopic data of 6–10 are discussed.
Synthesis and Biological Activity of Tetrahydropyrido[2′,3′:4,5]imidazo[1,2‐c]pyrimidine‐6,8‐diones
Authors: Sraga Jan , Guerry Philippe , Kompis Ivan 
Published: December 2004

AbstractSubstituted 4‐oxoquinoline‐3‐ (1a) and 4‐oxo‐1,8‐naphthyridine‐3‐ (1b) carboxylic acids are clinically useful antibacterial agents exerting their activity by inhibiting the subunit A of DNA gyrase. Recently, pyrimido‐[1,6‐a]benzimidazoles 2 were found to be a new class of inhibitors of this enzyme. As, in 1, replacement of C(8) by the N‐atom was shown beneficial for the biological properties, a synthesis of the corresponding aza analogues of 2 has been carried out. The synthesis, DNA gyrase inhibitory activity, and in vitro antibacterial activity of the target compounds 16–19 are reported.
Stereoselective Syntheses of Tetrahydroesterastin‐β ‐Lactam Analogues
Authors: Huber Isabelle , Schneider Fernand 
Published: December 2004

AbstractA total synthesis of the optically active tetrahydroesterastin β ‐lactam analogue 2 using Miller's hydroxamate approach is described (Scheme 2). Significant modification of published procedures has resulted in a short and facile stereospecific preparation of the N‐[(benzyloxycarbonyl)methyl]‐β ‐lactam 17 starting from the readily available D‐serine. This material served as intermediate for the preparation of a variety of N‐[(benzyloxycarbonyl)methyl]tetrahydroesterastin β‐lactam analogues (Scheme 5).
Reaktion von Phenyldiazomethan mit 1,3‐Thiazol‐5(4H)‐thionen: Basenkatalysierte Ring‐Öffnung des Primäradduktes
Authors: Petit Mireille , Linden Anthony , Heimgartner Heinz , Mlostoń Grzegorz 
Published: December 2004

Reaction of Phenyldiazomethane with 1,3‐Thiazole‐5(4H)‐thiones: Base‐Catalyzed Ring Opening of the Primary AdductReaction of 1,3‐thiazole‐5(4H)‐thiones 1 and phenyldiazomethane (2a) in toluene at room temperature yields the thiiranes trans‐ and cis‐1,4‐dithia‐6‐azaspiro[2.4]hept‐5‐enes (trans‐ and cis‐4; Scheme 2). With Ph3P in THF at 70°, these thiiranes are transformed stereospecifically into (E)‐ and (Z)‐5‐benzylidene‐4,5‐dihydro‐1,3‐thiazoles 5, respectively. In the presence of DBU, 1 and 2a react to give 1,3,4‐thiadiazole derivatives 6 or 7 via base‐catalyzed ring opening of the primary cycloadduct (Scheme 3). In the case of 2‐(alkylthio)‐substituted 1,3‐thiazole‐5(4H)‐thiones 1c and 1d, this ring opening proceeds by elimination of the corresponding alkylthiolate, yielding isothiocyanate 7. The structures of (Z)‐5c and 6b have been established by X‐ray crystallography.
Peptide Enolates. C‐Alkylation of Glycine Residues in linear tri‐, tetra‐, and pentapeptides via dilithium azadienediolates
Authors: Bossler Hans G. , Seebach Dieter 
Published: December 2004

AbstractThe Boc‐protected tripeptides Boc‐Val‐Gly‐Leu‐OH (1), Boc‐Leu‐Sar‐Leu‐OH (2), Boc‐Leu‐Gly‐MeLeu‐OH (3), and Boc‐Val‐BzlGly‐Leu‐OMe (64), tetrapeptide Boc‐Leu‐Gly‐Pro‐Leu‐OH (9), and pentapeptides Boc‐Val‐Leu‐Gly‐Abu‐Ile‐OH (4), Boc‐Val‐Leu‐Sar‐MeAbu‐Ile‐OH (5), Boc‐Val‐Leu‐Gly‐MeAbu‐Ile‐OH (6), Boc‐Val‐Leu‐BzlGly‐BzlAbu‐Ile‐OH (7), and Boc‐Val‐Leu‐Gly‐BzlAbu‐Ile‐OH (8) are prepared by conventional methods (Schemes 4–7) or by direct benzylation of the corresponding precursors (Scheme 8). Polylithiations in THF give up to Li6 derivatives containing glycine, sarcosine or N‐benzylglycine Li enolate moieties (A–H). The polylithiated systems with a dilithium azadienediolate unit (C, F–H) are best generated by treatment with t‐BuLi. The yields of alkylation of the glycine or sarcosine residues are up to 90%, with diastereoselectivities from nil to 9:1. Normally, the newly formed stereogenic center has (R)‐configuration (i.e. a D‐amino‐acid residue is incorporated in the peptide chain). Electrophiles which can be employed with the highly reactive azadienediolate moiety are: MeI, EtI, i‐PrI, allyl and benzyl bromide, ethyl bromoacetate, CO2, and Me2S2 (Schemes 11–13). No epimerizations of the starting materials (racemization of the amino‐acid residues) are observed under the strongly basic conditions. Selected conformations of the peptide precursors, generated by shock‐freezing or by very slow cooling from room temperature to −75° before lithiation, give rise to different stereoselectivities (Scheme 11). The latter and the yields can also be influenced by tempering the lithiated species before (Scheme 9) or after addition of the electrophiles (Scheme 12). Besides the desired products, starting peptides are recovered in the chromatographic purification and isolation procedures (material balance 80–95%). The results described are yet another demonstration that peptides may be backbone‐modified through Li enolates, and that whole series of analogous peptide derivatives with various side chains may thus be produced from a given precursor.
N‐(4‐Nitrophenyl)oxamic Acid and Related N‐Acylanilines Are Non‐competitive Inhibitors of vibrio cholerae sialidase but do not inhibit trypanosoma cruzi or trypanosoma brucei trans‐sialidases
Authors: Engstler Markus , Schauer Roland , Ferrero‐García Miguel A. , Parodi Armando J. , Storz‐Eckerlin Thomas , Vasella Andrea , Witzig Christian , Zhu Xiaoying 
Published: December 2004

AbstractN‐(4‐Nitrophenyl)oxamic acid 1, N‐(2‐fluoro‐4‐nitrophenyl)oxamic acid 7, N‐(4‐nitrophenyl)‐trifluoroacetamide 3, and N‐(2‐methoxy‐4‐nitrophenyl)trifluoroacetamide 9 are non‐competitive inhibitors of Vibrio cholerae sialidase with Ki‐values ranging from 2.66 to 5.18 · 10−4 M. These compounds, and the N‐acetylneuraminic‐acid analogues 11–13 do not inhibit the sialidase and trans‐sialidase activities from Trypanosoma cruzi; nor does N‐(4‐nitrophenyl)oxamic acid (1) inhibit the corresponding enzyme activities from T. brucei.
The Asymmetric Synthesis of Fused Cyclopentenone Ring Systems: A formal asymmetric total synthesis of (−)‐isocomene
Authors: Meyers Albert I. , Bienz Stefan , Kwon Hyok‐Boong , Wallace Richard H. 
Published: December 2004

AbstractOptically active tricyclic oxazolidine lactams 10 have been prepared using two different routes (Scheme 1). They can be obtained by acid‐mediated intramolecular cyclization of bicyclic lactams 13 via their acyliminium intermediates producing appended five‐, six‐, and seven‐membered tricyclic systems. Alternatively, 10 can be prepared by cyclocondensation of chiral amino alcohols with cyclopentane‐1,2‐dicarboxylic acids 12 to give the imide which is reduced or alkylated to the amino alcohols and cyclized to a diastereoisomer mixture of 10. Alkylation of 10 (R″ = H) via its enolate gives stereospecifically α‐quaternary products 10 (R″ = alkyl). Degradation of the latter with MeLi or Red‐Al® followed by mild acid hydrolysis and aldol cyclization produces the bicyclic ketones 14 and 15 as 1:1 mixtures, readily separated and isolated in > 99% ee. This sequence produced a known non‐racemic intermediate 69 for the synthesis of (−)‐isocomene.
A Novel Asymmetric Benzoin Reaction Catalyzed by a Chiral Triazolium Salt. Preliminary communication
Authors: Enders Dieter , Breuer Klaus , Teles J. Henrique 
Published: December 2004

AbstractUsing the chiral triazolium salt 1 as catalyst, a novel asymmetric variant of the benzoin reaction is reported. For the first time, the scope of the method is extended to a broader range of aromatic aldehydes 2, affording the acyloins 3a–h in yields of 22–72% and enantiomeric excesses up to 86%.
N,N‐Dialkylcarbamato Complexes of the d10 cations of copper, silver, and gold
Authors: Alessio Rocco , Dell'Amico Daniela Belli , Calderazzo Fausto , Englert Ulli , Guarini Alessandro , Labella Luca , Strasser Peter 
Published: December 2004

AbstractThe reaction of CuO'Bu with CO2, and iPr2NH in the presence of PPh3, gives the dialkylcarbamato complex [Cu(O2CNiPr2)(PPh3)2] (1). The CO2/R2NH system (R = Me, Et) in an appropriate organic medium reacts with Ag2O giving the corresponding N,N‐dialkylcarbamato complexes of analytical formula [Ag(C2CNR2)] (R = Me, 2; R = Et, 3). The methyl derivative 2 was characterized by X‐ray diffraction methods. Crystal data of 2: for [Ag2(O2CNMe2)2], C6H12Ag2N2O4, mol. wt. 391.9; monoclinic, space group P21/c, a = 12.08(1), b = 3.797(2), c = 11.316(7) Å, β = 113.37(6)°, V = 476.3 Å3, Z = 2, Dc = 2.732 g cm−3; μ(MoKα) = 40.64 cm−1, F(000) = 376.0; R = 0.059, Rw = 0.067; g.o.f. 1.27. The structure consists of dinuclear [(Ag2OCNMe2)2] units with slightly distorted linearly two‐coordinated Ag‐atoms containing bridging carbamato groups to form a substantially planar eight‐membered ring with an intra‐annular AgAg distance of 2.837(2) Å; the dinuclear units are further joined by AgO bonds to form an infinite array. Compound 3, which is presumably dinuclear, as suggested by cryoscopic measurements in benzene, undergoes a structural fission with PPh3, giving the mononuclear triphenylphosphine derivative [Ag(O2CNEt2)(PPh3)2] (4). The amine‐catalyzed conversion of Ag2O into Ag2CO3, in the presence of the iPr2NH/CO2 system, is also reported. Cl‐Exchange from [AuCl(PPh3)] with [Ag(O2CNEt2)] (3) gives the first N,N‐dialkylcarbamato complex of gold, namely [Au(O2CNEt2)(PPh3)] (5), which crystallizes in the monoclinic system: C23H25AuNO2P · 0.5 C7H16, mol. wt. 625.5, space group P21/c; a = 13.212(5), b = 12.25(1), c = 16.795(6) Å, β = 109.09(2)°, V = 2568(2) Å3, Z = 4, Dc, = 1.618 g cm−3; μ(AgKα) = 31.40 cm−1, F(000) = 1236.0; R = 0.058; Rw = 0.064; g.o.f. 2.121. The compound contains two‐coordinated Au‐atom, namely to the P‐atom and to the O‐atom of the monodentate carbamato group, the PAuO bond angle being 174.7(3)°. The reaction with MeI showed these compounds to react predominantly at the carbamato O‐atom giving the corresponding urethanes R2NCO2Me. Evidence was gathered for the transient coordination of CO to Ag in 3.
Structure and Dynamics of Hydrogen Chelates. Part 1. NMR‐spectroscopic studies in the quinazoline‐2‐acetonitrile series
Authors: Gehring Holger , Daltrozzo Ewald 
Published: December 2004

AbstractTo get informations on both the structure and dynamics of hydrogen chelates 1 of heteroaromatic systems, a great variety of quinazoline‐2‐acetonitrile chelates were synthesized (see 2–4). Similarly to the situation of the corresponding H‐chelates in the pyrimidine‐2‐acetonitrile series, the investigation of these new derivatives 2–4 by NMR spectroscopic methods (DNMR, COSY, NOESY, ROESY, EXSY, HMQC, HMBC) confirms the presence of an equilibrium of the two possible H‐chelate structures (two ‘rotamers’ I and II, i.e., (E)/(Z) isomers; see Scheme). The corresponding equilibria I ⇌ II were determined by complete 1H‐NMR signal assignment at low temperatures (after freezing the rotational processes). In addition, the tautomer equilibria A ⇌ B (relative energies of the two minima of the nonsymmetrical double‐well potential) for both ‘rotamers’ are ascertained by H,H and C,H couplings. The results are an important basis for the interpretation of both the UV/VIS absorptions and the dependence of fluorescence and fluorescence quantum yields on temperature.
Cyclopalladation of 1,1′‐Azonaphthalene (= Di(naphthalen‐1‐yl)diazene): Isolation and characterization of two isomeric complexes
Authors: Kind Lothar , Klaus Alfred J. , Rys Paul , Gramlich Volker 
Published: December 2004

AbstractThe cyclopalladation of 1,1′‐azonaphthalene (= di(naphthalen‐1‐yl)diazene; 2) with bis(hexafluoroacetyl‐acetonato)palladium(II) (3; [Pd(hfa)2]) yields the ortho‐palladated complex (1,1,1,5,5,5‐hexafluoropentane‐2,4‐dionato‐κ2O,O′)[1‐(naphthalen‐1‐ylazo‐κN2)naphthalen‐2‐yl‐κC2]palladium(II) (4) as well as the peri‐palladated complex (1,1,1,5,5,5‐hexafluoropentane‐2,4‐dionato‐κ2O,O′)[8‐(naphthalen‐1‐ylazo‐κN2)naphthalen‐1‐yl‐κC1]‐palladium(II) (5); their structures were corroborated by X‐ray analyses. The formation of the novel peri‐metallated product 5 containing a six‐membered palladacycle strongly depends upon the reaction conditions.
Die Krystallstruktur von Adamantan (symm. Tri‐cyclo‐decan)
Authors: Nowacki Werner 
Published: December 2004

AbstractAdamantan C10H16 krystallisiert in der kubisch‐flächenzentrierten Raumgruppe T–F43m mit a = 9,426 ± 0,008 Å und Z = 4 Molekeln pro Elementarzelle. Die röntgenographisch bestimmte Dichte ist gleich 1,073 gem−3. Die C‐Atome befinden sich in den Punktlagen (16e) = X1X1X1,… und (24f) = X2 00,… mit X1 = 0,0944, ± 0,001 und X2 = 2 X1. Die Molekel hat die Konstitution von Fig. 1, der Krystall die Struktur von Fig. 5. Die Ableitung geschah auf rein krystallographisch‐röntgenographischem Wege unter Voraussetzung von tetraedrischen C‐Atomen. Die Resultate sind in vollkommener Übereinstimmung mit denen von S. Landa und V. Macháčcek bzw. V. Prelog und R. Seiwerth.
Production d'ozone par action de radiations ultraviolettes, émises par la lampe è vapeur de mercure, sur l'oxygène comprimé ou liquéfié
Authors: Briner E. , Karbassi H. 
Published: December 2004

AbstractEn utilisant des dispositions expérimentales et des méthodes de travail appropriées, on a étudié la production d'ozone par action, sur l'oxygène comprimé ou liquéfié, des radiations ultra‐violettes, filtrées ou non filtrées, émises par la lampe à vapeur de mercure.
Electronic states of general mixed crystals
Authors: Koutecký Jaroslav , Davison Sydney G. 
Published: December 2004

AbstractUp to now molecular‐orbital calculations of the electronic states of linear mixed crystals have been concerned only with binary systems such as AB, AB2, and A2B2. The purpose of the present treatment is to extend this work to crystals whose elementary cells contain any number of different atoms in any ordered sequence. The formulation of this general theory is based on the resolvent method. Although the approach enables the general properties of delocalized and localized states to be discussed, the more simple cases already solved in the literature can still be easily derived from the general equations. Furthermore, the classification of Tamm and Shockley states retains its significance, even when other kinds of states can occur and various transitions between the clear cut cases can exist. As in earlier investigations, the chemisorption states are related to surface states and have similar properties. The resolvent method is summarized in the Appendix and its connection with the partition technique is shown.
Studies in perturbation theory XIII. Treatment of constants of motion in resolvent method, partitioning technique, and perturbation theory
Authors: Löwdin Per‐Olov 
Published: December 2004

AbstractAfter a brief survey of some basic concepts in the theory of linear spaces, the eigenvalue problem is formulated in the resolvent technique based on the introduction of a reference function φ and a complex variable ℰ. This leads to a series of fundamental concepts including the trial wave function, the inhomogeneous equation, and finally the transition and expectation values of the Hamiltonian, of which the former renders a “bracketing function” for the energy. In order to avoid the explicit limiting procedures in this approach, the eigenvalue problem is then reformulated in terms of the partitioning technique which, in turn, leads to a closed form of infinite‐order perturbation theory.The eigenvalue problem is greatly simplified if the Hamiltonian H has a constant of motion Λ or has symmetry properties characterized by the group G = {g}, and the question is now how these simplifications can be incorporated into the partitioning technique and into perturbation theory. In both cases, there exists a set of projection operators {Qk} which lead to a splitting of the Hilbert space into subspaces which have virtually nothing to do with each other. It is shown that, in the partitioning technique, it is sufficient to consider one of these subspaces at a time, and the results are then generalized to perturbation theory. It turns out that the finite‐order expansions are no longer unique, and the commutation rules connecting the various forms are derived. The infinite‐order results are finally presented in such a form that they are later suitable for the evaluation of upper and lower bounds to the energy eigenvalues.
Formal Rayleigh–Schrödinger perturbation theory for both degenerate and non‐degenerate energy states
Authors: Hirschfelder Joseph O. 
Published: December 2004

AbstractUsing the Rayleigh‐Schrödinger perturbation formalism, expressions are obtained for the nth order energy and the nth order wave function. No restrictions are placed on the degeneracy of the state or the order of perturbation in which the degeneracies are resolved. By the use of suitable operators, the formulae are expressed in compact form.
Electrostatic representations of molecular groups
Authors: Stigter Dirk , Schellman John A. 
Published: December 2004

AbstractThe treatment of electrostatic interactions between molecular groups is based on quantum mechanical electron density distributions. A general method is suggested using tesseral harmonic multipole expansions and representing each set of point multipoles by a cluster of discrete charges small with respect to atomic dimensions. The procedure is carried out for the amino group with an electron density derived from the wave function of ammonia. We evaluate the optical rotation of two aminopyrrolidones as a test case. Expansions are compared for several approximate wave functions for ammonia.
Spin‐free quantum chemistry. XII. Coarse structure magnetic theory
Authors: Matsen F. A. , Ford A. L. 
Published: December 2004

AbstractThe coarse structure magnetic theory presented here is a reformulation of conventional magnetic theory which emphasizes the spin‐free (i.e., the coulombic) nature of the electron‐electron interaction. We show that the magnetic properties of a system for which fine and hyperfine structure can be neglected depend only on the energy spectrum of a spin‐free Hamiltonian. As an example, we treat the Heisenberg linear chain.
Waller–Hartree spin‐free method
Authors: Lim T. K. 
Published: December 2004

AbstractIn this paper we show that with the equivalent transformation Pr = (−1)P(Pσ)−1 the spin function dependent methods such as Slater's method without group theory or Goddard's method with group theory differ only in different antisymmetric requirements from the present Waller‐Hartree spin function free method. There exists a one‐to‐one correspondence between Slater's determinantal wave function and the Waller–Hartree double determinantal wave function. Explicit expressions for the S2 operator, Löwdin's spin projector, matric basis and several different forms of spin‐projected functions are given for the Waller–Hartree formalism. The results are compared with other methods including those of Slater, Matsen, Gallup, Goddard and Segal. The differences are quite significant. New spin operators are worked out using creation‐destruction operators. A knowledge of group theory is not required in this Waller–Hartree method. We have also shown that the Waller–Hartree method is more convenient than Slater's method with spin functions especially in the evaluation of the functional ℋ︁Ψ/Ψ. The advantages and disadvantages in the use of a linear combination of N! Hartree products and linear combinations of all possible double determinants are discussed. In addition, a formula for the calculation of the Sanibel coefficients C(S, M, i) is obtained.