摘要:

AbstractInfectious RNA molecules lacking a protein coat have recently been shown to be the cause of several diseases in higher plants. These molecules, termed viroids, have been characterized as circular chains composed of about 360 nucleotide residues. They therefore comprise a class of infectious pathogens even smaller than viruses or bacteriophages. As a result of work on viroids it is now possible for the first time to give a complete description of the structure of a eukaryotic pathogen. Viroids possess structural and dynamic properties which have not as yet been observed with other nucleic acids. This article summarizes and discusses the results of predominantly biochemical and physicochemical studies on viroids.

ISSN:0570-0833    

DOI:10.1002/anie.198002313

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractIn this article the numerous intramolecular reactions of electronically excited benezene derivatives, which in many instances are only mentioned in original papers, are systematically analyzed and arranged according to reaction types. All known reaction types can be classified, and subdivided into reactions of the benzene ring (ionization, ring opening, ring alteration), reactions with participation of side chains (α‐, β‐, γ‐cleavage, homolysis, heterolysis), reactions of substituents with side chains (cyclization, dealkylation, cleavage of protective groups), and reactions of side chains with the aromatic ring (substitution, addition, dearomatization, cyclization). The selectivity of the energetically feasible competing reactions is primarily determined by geometric factors. Applications of the empirical effects are numerous and varied in preparative organic chemistry. Many of the reactions under discussion are already utilized industrially (e.g.in photochromism, UV stabilization, photography, information storage, printing, coating and polymer technology, and p

ISSN:0570-0833    

DOI:10.1002/anie.198002431

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractHeterocyclic three‐membered rings with an exocyclic double bond merit special interest in view of their ring strain and their fascinating chemistry. Their synthesis, thermal decomposition, ring opening, and cycloaddition reactions will be discussed in this review. α‐Lactams, alkylideneaziridines, diaziridinones, and diaziridinimines belong to the best known classes, but the chemistry of alkylideneoxiranes and ‐thiiranes, α‐lactones, α‐thiolactones, thiiranimines, and aziridinimines has also been studied to some extent. Two elusive three‐membered rings are oxiranimines and thiaziridinimines; the former were postulated as reactive intermediates in the thermal decomposition of α‐lactams, whereas the latter were trapped efficiently with double and triple bonds during thermolysis ofN‐sulfonyliminothiatriazolines. In spite of many attempts to prepare thione derivatives of the title compounds, they are still unknown. Included in this review are also some open‐chain dipolar species which are isomeric with the heterocyclic

ISSN:0570-0833    

DOI:10.1002/anie.198002761

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

摘要:

AbstractThe electronic spectra of complexes are especially informative if they are recorded for crystals at low temperature or at varying temperature with polarized light. This straightforward technique frequently permits reliable band assignment. Such assignments, being independent of the assumptions of any particular theoretical model, then provide a basis for testing theories of electronic structure.

ISSN:0570-0833    

DOI:10.1002/anie.198002901

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198003011

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198003032

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198003041

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198003061

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198003071

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.198003082

出版商:Hüthig&Wepf Verlag    

年代:1980

数据来源: WILEY