摘要:

AbstractOur knowledge concerning the relationships between the structure and mass spectra of organic compounds has widened immensely during the past few years. It has become possible to alter the course of fragmentation in the mass spectrometer by changing certain substituents using simple chemical reactions. The fragmentation products formed are then entirely different from those of the starting material. A combination of controlled mass‐spectrometric decomposition with chemical microreactions often permits the solution of complicated structural problems with a minimum expenditure of time and material. One example for the alteration of the fragmentation pattern by a simple chemical reaction is discussed in connection with the elucidation of the structure of pleiocarpamin

ISSN:0570-0833    

DOI:10.1002/anie.196503831

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractVarious chemical procedures are available for studying the sequence distribution in copolymers, but none can be applied routinely. The run‐number approach permits the results of such studies to be treated with ease; all results obtained to date are consistent with classical copolymerization theor

ISSN:0570-0833    

DOI:10.1002/anie.196503941

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractImportant advances have recently been made in the chemisty of the lower oxides of sulfur, both in the preparative sphere and by the application of modern physical methods of investigation. In this paper the knowledge gained to date on the compounds SO, S2O2, S2O, S2O3, and the polysulfur oxides is reviewed and critically appraised.

ISSN:0570-0833    

DOI:10.1002/anie.196504021

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractProstaglandins occur in many animal species and tissues. They are C20‐carboxylic acids contining one five‐membered ring, one keto group, two or three hydroxy groups, and one to three CC double bonds. Their structures were elucidated by chemical, radiochemical, and physical methods in combination with gas chromatography and mass spectrometry. The prostaglandins are biosynthesized from essential fatty acids. By their action smooth muscles are stimulated and lipid metabolism is aff

ISSN:0570-0833    

DOI:10.1002/anie.196504101

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

摘要:

AbstractThe term silylation is used to denote the introduction of a triorganosilyl moiety, especially the trimethylsilyl species, into organic compounds. ‐ Silylated amino acids and sugars are particularly suitable for the syntheses of peptides and saccharides, respectively, since the silyl group can be cleaved off readily under mild conditions. Many diamines undergo ring closure, e.g. with phosgene, only after silylation. ‐ O‐silylated lactim ethers (i.e. cyclic imino ethers) are converted into N‐alkyl derivatives by alkyl halides. Compounds with a strongly polarized SiC bond may be used for chain extension. Silyl esters of halogeno fatty acids yield lactones with silver cyanate. ‐ Trimethylsilyl azide is thermally very stable and behaves like organic azides. It reacts with acetylenic compounds, trialkylphosphines, and triarylphosphines to yield silylated triazole derivatives, trialkylphosphines N‐silylimines, and triarylphosphines to yield silylated triazole dervatives, trialkylphosphine N‐silylimines, and triarylphosphine N‐silylimines, respectively, from which the silyl groups can be removed unde

ISSN:0570-0833    

DOI:10.1002/anie.196504171

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196504291

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196504301

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196504312

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196504322

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.196504333

出版商:Hüthig&Wepf Verlag    

年代:1965

数据来源: WILEY