Angewandte Chemie International Edition

Heusler, K.; Kalvoda, J.

doi: 10.1002/anie.196405251pmid: N/A

In the present article an attempt is made to summarize the steric requirements and the influence of neighboring groups which determine the course of intramolecular radical reactions. Steroids are used as substrates for these reactions, since here the spatial arrangement of the ring members and the distances between substituents are largely fixed. Furthermore, intramolecular free‐radical reactions are of practical importance in steroid chemistry in connection with substitution at non‐activated carbon atoms. Almost all the reactions discussed begin with the formation of an oxygen radical by oxidation of an alcohol with lead tetraacetate or by homolysis of the corresponding hypoiodite.

Hoppe, R.

doi: 10.1002/anie.196405381pmid: N/A

Schill, G.; Lüttringhaus, A.

doi: 10.1002/anie.196405461pmid: N/A

Hünig, S.

doi: 10.1002/anie.196405481pmid: N/A

The effect of the nature of the coreactants and the reaction conditions on the ability of certain mesomeric cations to react with nucleophilic reagents to form isomeric products has been studied. The structures of the products isolated are determined by competition between a kinetically controlled but reversible reaction and a thermodynamically controlled reaction.

Gompper, R.

doi: 10.1002/anie.196405601pmid: N/A

Theoretical considerations and recent experimental results have added greatly to our knowledge of the structures and reactivities of ambifunctional nucleophilic compounds during the last few years. In the present work an attempt is made to present a survey of the theories which have been developed to explain the behavior of these compounds towards electrophilic reagents, and to formulate rules which may serve as guides for carrying out new reactions.

Luck, W.; Sand, H.

doi: 10.1002/anie.196405701pmid: N/A

A short survey of the present status of our knowledge in the field of “phototrophy” is presented. The laws which govern this phenomenon are described, taking parafuchsin and N,N′‐di‐methyl‐1,4‐diaminoanthraquinone as examples. Phototropy and thermotropy are related. The acceleration of the regression of phototropically induced states by irradiation with light is discussed in some detail. An understanding of phototropy promises insight into the mechanisms of photochemical reactions and into the prerequisites for the preparation of light‐fast dyes.

Fischer, E. O.; Maasböl, A.

doi: 10.1002/anie.196405801pmid: N/A

Viehe, H. G.; Fuks, R.; Reinstein, M.

doi: 10.1002/anie.196405811pmid: N/A

Masamune, S.; Castellucci, N. T.

doi: 10.1002/anie.196405821pmid: N/A

Buijle, R.; Viehe, H. G.

doi: 10.1002/anie.196405822pmid: N/A