bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trivelpiece‐Gould mode produced gas‐discharges in a diffusion‐controlled regime
Authors: Schlüter H. , Shivarova A. , Tarnev Kh. 
Published: July 2003

AbstractThe study presents a numerical fluid‐plasma model of waveguide discharges sustained by travelling azimuthallysymmetric Trivelpiece‐Gould modes. The results describe weakly‐magnetized (ω ≥ Ωe) plasma production in a diffusion‐controlled regime (ω being the wave frequency, Ωe the electron gyro‐frequency). However, with respect to the influence of the external magnetic field on the transverse ambipolar‐diffusion coefficient, cases of both weak and strong impact of the magnetic field are covered. In its electrodynamical part, the model involves detailed description of the behaviour of the Trivelpiece‐Gould waves in radially‐inhomogeneous collisional plasmas. The gas‐discharge part of the model specifies plasma production in an argon gas. The results are for the self‐consistent structure of the discharge composed out of the interrelated variations of wavenumber, space damping rate, plasma density, electron temperature and power absorbed on average by an electron. The analysis is in terms of influence of gas‐pressure and magnetic‐field changes.
The vacuum arc cathode spot and plasma jet: Physical model and mathematical description
Authors: Beilis I. I. 
Published: July 2003

AbstractA physical model of the cathode processes and flow of material eroded from the cathode of a vacuum arc is formulated. The model considers the plasma jet and the plasma generation regions, and provides electrical current continuity at the metal‐plasma boundary in the cathode spot. Based on an analysis of the kinetics of cathodic evaporation and plasma flow in the hydrodynamic region, a closed system of equations is obtained. Boundary conditions for the cathodic plasma expansion are formulated. The system of equations allows to compute the spot parameters (cathode potential drop, cathode material erosion rate, plasma parameters ‐velocity, density, temperature, e.t.c) using a self‐consistent description of the plasma flow in the cathode spot and cathode jet regions. The calculations for spot currents 1 ‐ 20 A show that the cathode potential drop increases, erosion rate decreases with spot current and spot life time decreasing.
Iron(III) Chelation: Tuning of the pH Dependence by Mixed Ligands
Authors: Albrecht‐Gary Anne‐Marie , Blanc Sylvie , Biaso Frederic , Thomas Fabrice , Baret Paul , Gellon Gisele , Pierre Jean‐Louis , Serratrice Guy 
Published: July 2003

AbstractThe iron(III) chelating properties of two heteropodands with 8‐hydroxyquinoline and catechol binding groups were examined and compared to those of the corresponding homopodal analogues, O‐TRENSOX and TRENCAMS. Like the parent homopodands, the two heteropodands are based on the TREN scaffold and the chelating units are connected by amide groups, TRENSOX2CAMS having two 8‐hydroxyquinoline and one catechol arms and TRENSOXCAMS2 one 8‐hydroxyquinoline and two catechol moieties. The aqueous coordination chemistry of these ligands was examined by potentiometric and spectrophotometric methods in combination with 1H NMR spectroscopy. The respective pFeIII values showed a cooperative effect of the mixed chelating units. Moreover, the pFeIII dependence on pH showed that the mixed ligands exhibit a higher complexing ability than the parent ligands over the pH range 5−9 which is of biological relevance. This result could be of great interest for medical applications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Syntheses and Crystal Structures of Two Novel Zinc(II) Coordination Polymers
Authors: Tao Jun , Yin Xin , Jiang Yun‐Bao , Yang Le‐Fu , Huang Rong‐Bin , Zheng Lan‐Sun 
Published: July 2003

AbstractTwo novel zinc(II) coordination polymers, [Zn3(μ3‐OH)2(nip)2] (1) and [Zn2(nip)2(4,4′‐bpy)3·(OH2)] (2) (H2nip = 5‐nitroisophthalic acid, 4,4′‐bpy = 4,4′‐bipyridyl), were obtained by the hydrothermal reactions of zinc nitrate, 5‐nitroisophthalate (nip) (for 1) and zinc nitrate, 5‐nitroisophthalate and 4,4′‐bipyridyl (for 2). Complex 1 displays a two‐dimensional structure that is built from [Zn3(μ3‐OH)2]n chains, while complex 2 is a three‐dimensional structure formed by the interpenetration of two‐dimensional hydrogen‐bonded bilayers. The photoluminescent properties of complex 1 have also been investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Second‐Order Nonlinear Optical Properties of Tetraaza‐Coordinated Nickel(II) Complexes
Authors: Di Bella Santo , Fragalà Ignazio 
Published: July 2003

AbstractIn this contribution, we report the design and theoretical analysis, using the INDO/SCI‐SOS quantum chemical formalism, of novel molecular architectures based on planar [N4]‐, (2‐aminobenzylideneiminato)‐ and tetraazamacrocycle‐coordinated nickel(II) complexes, having second‐order nonlinear optical (NLO) properties. Calculations indicate that these molecules possess comparable, or even larger, second‐order nonlinearity to the bis(salicylaldiminato)NiII Schiff‐base analogues. The nonlinearity of substituted complexes is dominated by the nature and position of substituents on the tribenzo[b,f,l] and/or cyclotetradecine rings, and is determined by the relative directions of the ground‐ and excited‐state dipole moments. Moreover, substitution with acceptor groups in the dibenzo[b,l] rings involves a significant octupolar contribution to optical nonlinearity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New Tris(pyrazolyl)triazine and Pyrazolylpyridine Gold(I) and Palladium(II) Derivatives Based on the 3,5‐Bis(4‐butoxyphenyl)pyrazole Group − Architectures with Different Types of Bonding Interactions
Authors: Claramunt Rosa M. , Cornago Pilar , Cano Mercedes , Heras José V. , Gallego M. Luz , Pinilla Elena , Torres M. Rosario 
Published: July 2003

AbstractThe 3,5‐bis(4‐butoxyphenyl)pyrazolyl group (Pzbp2) has been used as a building block for mono‐ and polymetallic derivatives of 2,4,6‐tris[3,5‐bis(4‐butoxyphenyl)pyrazol‐1‐yl]‐1,3,5‐triazine (TPzbp2Tz, 1), 2‐[3,5‐bis(4‐butoxyphenyl)pyrazol‐1‐yl]pyridine (Pzbp2Py, 2), and 3,5‐bis(4‐butoxyphenyl)pyrazole (HPzbp2, 3) ligands. The synthesis and characterisation of the new hexadentate ligand 1 are described, together with the chemistry of its metal complexes containing [Pd(η3‐C3H5)]+ and [Au(PPh3)]+ fragments. The related complexes containing Pzbp2Py (2) were also studied and their structural characteristics were compared to those of the TPzbp2Tz species. The role of the counter‐ion on the supramolecular assembly of complexes containing the HPzbp2 ligand 3 was made clear by the X‐ray structures of [Pd(η3‐C3H5)(HPzbp2)2](BF4) and [Au(HPzbp2)(PPh3)](NO3). Hydrogen bonds and/or bonding interactions are responsible for pseudohelical one‐dimensional polymers or supramolecular columnar arrays, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Crystal Structure and Fluorescence of Two Novel Mixed‐Ligand Cadmium Coordination Polymers with Different Structural Motifs
Authors: Luo Junhua , Hong Maochun , Wang Ruihu , Cao Rong , Han Lei , Lin Zhenzhong 
Published: July 2003

AbstractTwo novel cadmium(II) coordination compounds, [Cd(bpe)1.5(NO2‐BDC)]·0.25H2O (1) and [Cd(bpp)(NO2‐BDC)(H2O)]·0.25H2O (2) [NO2‐BDCH2 = 5‐nitro‐1,3‐benzenedicarboxylic acid, bpe = 1,2‐bis(4‐pyridyl)ethane, bpp = 1,3‐bis(4‐pyridyl)propane] have been hydrothermally synthesized by reaction of cadmium chloride and NO2‐BDC with the homologous ligands bpe and bpp, respectively. The former compound displays a remarkable three‐dimensional architecture sustained by the catenation of 2D bilayers, while the latter exhibits a unique twofold interpenetrating three‐dimensional architecture. The thermal and fluorescence properties associated with their crystal structures have been measured. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture: Rhodium and Ruthenium Complexes of 1,1′‐Bis(phosphetano)ferrocenes: Structural Characterisation and Catalytic Behaviour (Eur. J. Inorg. Chem. 14/2003)
Authors: Marinetti Angela , Labrue Francis , Pons Bénédicte , Jus Sébastien , Ricard Louis , Genêt Jean‐Pierre 
Published: July 2003

AbstractThe cover picture shows the X‐ray crystal structures of ruthenium and rhodium complexes of chiral 1,1′‐bis(phosphetano)ferrocenes. These diphosphanes rank among the ligands inducing excellent enantioselectivities in rhodium‐promoted hydrogenations of prochiral olefins. X‐ray crystal structures of their metal complexes afford information about their coordinating behaviour and preferred conformations in catalytically active species. Details are discussed in the article by A. Marinetti et al. on p. 2583 ff.
Information seeking and reciprocity: a transformational analysis
Authors: Gallucci Marcello , Perugini Marco 
Published: July 2003

AbstractThe motivation to reciprocate is analyzed within the framework of interdependence theory, with focus on the process of transformation of situations. A model of transformation is presented for the motivation to reciprocate and hypotheses regarding allocation behavior and information seeking are derived. The hypotheses are tested in two experiments implementing a game where participants allocate payoff to self and other in a sequential way, with one participant able to gather costly information regarding the other's previous behavior. Individual differences in the motivation to reciprocate are assessed with the Personal Norm of Reciprocity questionnaire. Results show that participants with high motivation to reciprocate seek information regarding other's past behavior, and react to this information as the norm of reciprocity prescribes. Participants with low motivation to reciprocate prefer information regarding the future of the interaction (Study 1), or no information (Study 2), and behave in a more selfish way. Results are discussed with respect of (1) the transformation of situation process, (2) the role of reciprocity as an interpersonal motive, and (3) the validity of the individual differences measure. Copyright © 2003 John Wiley & Sons, Ltd.
Ingroup identification moderates stereotype change in reaction to ingroup deviance
Authors: Hutchison Paul , Abrams Dominic 
Published: July 2003

AbstractAn experiment (N = 98) investigated the moderating effect of ingroup identification on reactions to deviant ingroup members. We measured psychology students' level of identification with the group ‘psychologists’ and presented them with information about either a normative or deviant psychologist. Participants completed an ingroup stereotype measure either before or after reading about and evaluating the target psychologist. High identifiers expressed a more positive stereotype of the ingroup after, compared to before, reading about a deviant ingroup member. High identifiers also expressed a more positive stereotype of the ingroup after reading about a deviant than after reading about a normative ingroup member. By contrast, low identifiers' stereotype judgements were relatively unaffected by the target information. The target evaluation ratings indicate that high identifiers were more positive than low identifiers towards the normative ingroup member, but were more negative than low identifiers towards the deviant. The results point to the greater motivational demands on high identifiers to maintain a positive image of the group. Copyright © 2003 John Wiley & Sons, Ltd.
Why inconsistent leadership is regarded as procedurally unfair: the importance of social self‐esteem concerns
Authors: De Cremer David 
Published: July 2003

AbstractThree experimental studies examined to what extent leader's consistent use of procedures constitutes an important procedural fairness rule and influences people's reactions as a function of social self‐esteem. In line with a recent claim that more attention should be devoted to different procedural fairness rules (Brockner, Ackerman, & Fairchild, 2001), the findings of Study 1 demonstrated that inconsistent leaders were evaluated as less procedurally fair and influenced feelings of uncertainty about oneself in ongoing interpersonal interactions. Study 2 showed that manipulating leader's consistency influenced people's procedural fairness judgments and willingness to replace the leader, but only among those low in social self‐esteem (SSE). Finally, Study 3, using another consistency manipulation, demonstrated that variations in consistency made participants feel bad about themselves, particularly when they were low in SSE. These findings are discussed in light of research on relational models of justice and sociometer theory. Copyright © 2003 John Wiley & Sons, Ltd.
Von der Wiedergeburt einer großen Bibliothek
Authors: Künast Hans‐Jörg , Zäh Helmut 
Published: July 2003

AbstractIn detektivischer Kleinarbeit wird die Bücher‐ und Handschriftensammlung des Augsburger Stadtschreibers Konrad Peutinger rekonstruiert. Der Zeitgenosse Luthers baute eine der bedeutendsten Humanistenbibliotheken seiner Zeit auf
Die Heuschrecke und der Kurvenflug
Authors: Kutsch Wolfram , Berger Sebastian , Fischer Hanno 
Published: July 2003

AbstractMit Hilfe miniaturisierter Daten‐Fernübertragung untersuchen Biologen die Flugbewegungen freifliegender Wüstenheuschrecken und anderer Insekten. Computergestützte Videotechnik rekonstruiert Verhaltensabläufe
Die Arbeitslosen und die Solidarität
Authors: Hamann Silke , Karl Astrid 
Published: July 2003

AbstractDie grassierende Massenarbeitslosigkeit und die Diskussion um die Zukunft sozialer Sicherung werfen viele Fragen auf. Wie sozialstaatliche Leistungen für Arbeitslose in der Bevölkerung akzeptiert werden, beantwortet eine Studie
Influence of β‐Alanine on Hairpin Polyamide Orientation in the DNA Minor Groove
Authors: Rucker Victor C. , Melander Christian , Dervan Peter B. 
Published: July 2003

AbstractAntiparallel polyamides containing 1H‐pyrrole, 1H‐imidazole, and 3‐hydroxy‐1H‐pyrrole amino acids display a preference for minor‐groove binding oriented NC with respect to the 5′‐3′ direction of the DNA helix. We find that replacement of a central Py/Py pair with a β/β pair within a ten‐ring hairpin relaxes the orientation preference and, for some DNA sequences, causes the polyamide to prefer the opposite CN orientation. Substitution of the achiral γ‐aminobutanoic acid (γ) with either (R)(or S)‐2‐(acetylamino)‐4‐aminobutanoic acid moderates the orientation preference of the 2‐β‐2‐hairpin.
Synthesis and Glycosidase Inhibitory Activities of 5‐(1′,4′‐Dideoxy‐1′,4′‐imino‐D‐erythrosyl)‐2‐methyl‐3‐furoic Acid (=5‐[(3S,4R)‐3,4‐Dihydroxypyrrolidin‐2‐yl]‐2‐methylfuran‐3‐carboxylic Acid) Derivatives: New Leads as Selective α‐L‐Fucosidase and β‐Galactosidase Inhibitors
Authors: Moreno‐Vargas Antonio J. , Robina Inmaculada , Demange Raynald , Vogel Pierre 
Published: July 2003

AbstractThe García‐González reaction of D‐glucose and ethyl acetoacetate generated ethyl 5‐[(1′S)‐D‐erythrosyl]‐2‐methyl‐3‐furoate (5), which was converted to ethyl 5‐[(1′R)‐1′,4′‐dideoxy‐1′,4′‐imino‐D‐erythrosyl]‐2‐methyl‐3‐furoate (3c) and to ethyl 5‐[(1′S)‐1′,4′‐dideoxy‐1′,4′‐imino‐D‐erythrosyl]‐2‐methyl‐3‐furoate (4c). Similar methods were developed to generate other carboxylic acid derivatives such as methyl (see 3e and 4e), isopropyl (see 3f), and butyl esters (see 3g), S‐phenyl (see 3a) and S‐ethyl thioesters (see 3m), N‐benzylcarboxamides 3b and 4b, glycine‐derived amide 3h, and N‐phenyl (see 3i), N‐isopropyl (see 3j and 4j), N,N‐diethyl‐ (see 3k and 4k), and N‐ethyl‐carboxamides (see 3l). All the new 5‐(1′,4′‐dideoxy‐1′,4′‐imino‐D‐erythrosyl)‐3‐furoic acid (=5‐[(3S,4R)‐3,4‐dihydroxypyrrolidin‐2‐yl)furan‐3‐carboxylic acid) derivatives 3 and 4 were assayed for inhibitory activity towards 25 commercially available glycosidases. Derivative 3a with a S‐phenyl thioester group is a good and selective α‐L‐fucosidase inhibitor (Ki=2–4 μM), whereas 4b (with a N‐benzylcarboxamide group) is a good β‐galactosidase inhibitor.
On the Reaction of Thiazole‐2,4‐diamines with Isothiocyanates – Preparation and Transformation of 2,4‐Diaminothiazole‐5‐carbothioamides
Authors: Hahnemann Cornelia , Hartmann Horst 
Published: July 2003

AbstractIn the reaction of thiazole‐2,4‐diamines 8 with isothiocyanates 1, 2,4‐diaminothiazole‐5‐carbothioamides 9, 10, 18, and 19 as well as thiazolo[4,5‐d]pyrimidine‐7(6H)‐thiones 21 were formed. The carbothioamides 9, 10, and 18 were transformed by reaction with different types of monofunctional and bifunctional electrophiles into hitherto unknown acceptor‐substituted 4,4′‐([2,5′‐bithiazole]‐2′,4′‐diyl)bis[morpholines] 24 and 29, the 2′,4′‐bis(dialkylamino)[2,5′‐bithiazol]‐4‐(5H)‐ones 30, and the 4‐substituted 2′,4′‐bis(dialkylamino)‐2,5′‐bithiazoles 31. From 30 and 31 new 4‐mono‐ or 4,5‐disubstituted 2′,4′‐bis(dialkylamino)‐2,5′‐bithiazoles 34, 35, 38, and 39 as well as 5‐substituted 2′,4′‐bis(dialkylamino)[2,5′‐bithiazol]‐4(5H)‐ones 33, 36, and 37 were prepared.
Cytotoxic Constituents of Piper sintenense
Authors: Chen Jih‐Jung , Duh Chang‐Yih , Huang Hung‐Yi , Chen Ih‐Sheng 
Published: July 2003

AbstractA new pyridone alkaloid, 5,6‐dihydro‐5‐hydroxy‐1H‐pyridin‐2‐one (1), and a new ester, sintenin (=3‐(3,4‐dimethoxyphenyl)propyl 3‐(3,4‐dimethoxyphenyl)propanoate 2), together with three known compounds, 5,6‐dihydro‐1H‐pyridin‐2‐one (3), d‐sesamin (=5,5′‐(3a,4,6,6a‐tetrahydro‐1H,3H‐furo[3,4‐c]furan‐1,4‐diyl)bis[1,3‐benzodioxole]; 4), and (E)‐phytol (=3,7,11,15‐tetramethylhexadec‐2‐en‐1‐ol; 5) have been isolated from the whole plant of Piper sintenense. The structures of the two new compounds were determined through spectral analyses. Among twenty isolates obtained so far, four compounds exhibited effective cytotoxicities against P‐388, HT‐29, or A549 cell lines in vitro.
Five Novel Taccalonolides from the Roots of the Vietnamese Plant Tacca paxiana
Authors: Mühlbauer Andrea , Seip Stephan , Nowak Alexander , Tran Van Sung 
Published: July 2003

AbstractChemical investigation of the roots of the Vietnamese plant Tacca paxiana resulted in the isolation of five new steroidal compounds, taccalonolide R (6), S (7), T (8), U (9), and V (10). Their structures were established on the basis of NMR and mass‐spectral data. In addition, the five known taccalonolides A (1), B (2), E (3), K (4), and N (5) were also isolated and identified.
Synthesis of 5′‐O‐(2‐Azido‐2‐deoxy‐α‐D‐glycosyl)nucleosides and Their Antitumor Activities
Authors: Zhang Gui‐Sheng , Chen Jie , Min Ji‐Mei , Zhang Li‐He 
Published: July 2003

AbstractThe 1,3,4,6‐tetra‐O‐acetyl‐2‐azido‐2‐deoxy‐β‐D‐mannopyranose (4) or the mixture of 1,3,6‐tri‐O‐acetyl‐2‐azido‐2‐deoxy‐4‐O‐(2,3,4,6‐tetra‐O‐acetyl‐β‐D‐galactopyranosyl)‐β‐D‐mannopyranose (10) and the corresponding α‐D‐glucopyranose‐type glycosyl donor 9/10 reacted at room temperature with protected nucleosides 12–15 in CH2Cl2 solution in the presence of BF3⋅OEt2 as promoter to give 5′‐O‐(2‐azido‐2‐deoxy‐α‐D‐glycosyl)nucleosides in reasonable yields (Schemes 2 and 3). Only the 5′‐O‐(α‐D‐mannopyranosyl)nucleosides were obtained. Compounds 21, 28, 30, and 31 showed growth inhibition of HeLa cells and hepatoma Bel‐7402 cells at a concentration of 10 μM in vitro.
Intercalating Nucleic Acids with Pyrene Nucleotide Analogues as Next‐Nearest Neighbors for Excimer Fluorescence Detection of Single‐Point Mutations under Nonstringent Hybridization Conditions
Authors: Christensen Ulf B. , Pedersen Erik B. 
Published: July 2003

AbstractFluorescence and hybridization specificity is reported for intercalating nucleic acids (INAs), which are here oligodeoxynucleotides (ODNs) synthesized with insertions using (S)‐1‐[bis(4‐methoxyphenyl)(phenyl)methoxy]‐3‐[(pyren‐1‐yl)methoxy]propan‐2‐ol phosphoramidites. It is shown that an INA with two insertions placed as next‐nearest neighbors can be used for discrimination between nucleic acids and their single‐point mutants. Quenching of an excimer band at 480 nm is observed upon hybridizing to a complementary sequence, whereas the excimer band is present when the nucleobase pair between the two pyrene moieties is mismatched. It is the first example of a solution based on fluorescence detection of single‐point mutants that uses excimer formation and does not rely on stringent hybridization conditions. Furthermore, it is shown that INAs with pyrene insertions retain their sequence specificity in thermal melting.
Evidence from Circular Dichroism and from Melting Behavior for Helix‐Inducing Complexation of a Designed β3‐Pentadecapeptide with DNA Duplexes. Preliminary Communication
Authors: Kimmerlin Thierry , Namoto Kenji , Seebach Dieter 
Published: July 2003

AbstractInspired by naturally occurring DNA‐binding proteins and their artificial α‐peptidic mimics reported to date, a research project was initiated aiming at creating a new class of β‐peptides capable of binding to and ultimately regulating the functions of DNA. As an initial foray, a β3‐pentadecapeptide 1, which bears H‐bonding Asn side chains and positively charged Lys side chains, was designed and synthesized on the solid support. DNA‐Complexation studies by means of circular dichroism and DNA‐melting‐temperature measurements revealed the first preliminary indications that support the existence of ordered interactions between β‐peptides and DNA.
Synthesis and Characterization of Ruthenium Complexes with Substituted Pyrazino[2,3‐f][1,10]‐phenanthroline (=Rppl; R=Me, COOH, COOMe)
Authors: Delgadillo Alvaro , Romo Paola , Leiva Ana Maria , Loeb Bárbara 
Published: July 2003

AbstractA series of substituted pyrazino[2,3‐f][1,10]‐phenanthroline (Rppl) ligands (with R=Me, COOH, COOMe) were synthetized (see 1–4 in Scheme 1). The ligands can be visualized as formed by a bipyridine and a quinoxaline fragment (see A and B). Homoleptic [Ru(R1ppl)3](PF6)2 and heteropleptic [Ru(R1ppl){(R2)2bpy}2](PF6)2 (R1=H, Me, COOMe and R2=H, Me) metal complexes 5–7 and 8–13, respectively, based on these ligands were also synthesized and characterized by conventional techniques (Schemes 2 and 3, resp.). In the heteroleptic complexes, the R1‐ppl ligand reduces at a less‐negative potential than the bpy ligand, reflecting the acceptor property conferred by the quinoxaline moiety. The potentiality of some of these complexes as solar‐cell dyes is discussed.
Oxidative Fragmentations of the 5α‐ and 5β‐Hydroxy‐B‐norcholestan‐ 3β‐yl Acetates
Authors: Bjelaković Mira S. , Lorenc Ljubinka B. , Pavlović Vladimir D. , Tinant Bernard , Declercq Jean‐Paul , Kalvoda Jaroslav 
Published: July 2003

AbstractOxidations of 5α‐hydroxy‐B‐norcholestan‐3β‐yl acetate (8) with Pb(OAc)4 under thermal or photolytic conditions or in the presence of iodine afforded only complex mixtures of compounds. However, the HgO/I2 version of the hypoiodite reaction gave as the primary products the stereoisomeric (Z)‐ and (E)‐1(10)‐unsaturated 5,10‐seco B‐nor‐derivatives 10 and 11, and the stereoisomeric (5R,10R)‐ and (5S,10S)‐acetals 14 and 15 (Scheme 4). Further reaction of these compounds under conditions of their formation afforded, in addition, the A‐nor 1,5‐cyclization products 13 and 16 (from 10) and 12 (from 11) (see also Scheme 6) and the 6‐iodo‐5,6‐secolactones 17 and 19 (from 14 and 15, resp.) and 4‐iodo‐4,5‐secolactone 18 (from 15) (see also Scheme 7). Oxidations of 5β‐hydroxy‐B‐norcholestan‐3β‐yl acetate (9) with both hypoiodite‐forming reagents (Pb(OAc)4/I2 and HgO/I2) proceeded similarly to the HgO/I2 reaction of the corresponding 5α‐hydroxy analogue 8. Photolytic Pb(OAc)4 oxidation of 9 afforded, in addition to the (Z)‐ and (E)‐5,10‐seco 1(10)‐unsaturated ketones 10 and 11, their isomeric 5,10‐seco 10(19)‐unsaturated ketone 22, the acetal 5‐acetate 21, and 5β,19‐epoxy derivative 23 (Scheme 9). Exceptionally, in the thermal Pb(OAc)4 oxidation of 9, the 5,10‐seco ketones 10, 11, and 22 were not formed, the only reaction being the stereoselective formation of the 5,10‐ethers with the β‐oriented epoxy bridge, i.e. the (10R)‐enol ether 20 and (5S,10R)‐acetal 5‐acetate 21 (Scheme 8). Possible mechanistic interpretations of the above transformations are discussed.