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Dive into the research topics where Klaus Annen is active.

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Featured researches published by Klaus Annen.


Tetrahedron | 1972

Die struktur des Jaborosalactons F

Rudolf Tschesche; Klaus Annen; Peter Welzel

Zusammenfassung Aus den Blattern von Jaborosa integrifolia wurde ein neues Withanolid, das Jaborosalacton F ( 1 ), isoliert. 1 lieferte bei Acetylierung das Triacetat 3 , aus dem durch Hydrierung das Dihydrodesoxy-Derivat 5 entstand. Die Strukturen wurden mit Hilfe der IR-, NMR-, MS- und CD-Spektren bestimmt.


Tetrahedron Letters | 1984

New 9,10-seco-steroids from 11β-hydroxy-8β,9-epoxy-derivatives

Klaus Annen; Helmut Hofmeister; Henry Laurent; Arne Seeger; Rudolf Wiechert

Abstract Reaction of readily available 11β-hydroxy-8β, 9-epoxy-steroids with hydrogen fluoride-pyridine gave the corresponding 9.10-seco-derivatives in good yields.


Archive | 1984

11β-arylestradienes, their production, and pharmaceutical preparations containing same

Ralph Rohde; Klaus Annen; Günter Neef; Rudolf Wiechert; Sybille Beier; Walter Elger; David Henderson


Archive | 1984

11-Beta-aryl-estradienes, process for their preparation and pharmaceutical compositions containing them

Günter Neef; Gerhard Sauer; Rudolf Wiechert; Helmut Hofmeister; Ralph Rohde; Klaus Annen; Henry Laurent; Sybille Dr. Beier; Wolfgang Losert; Walter Dr Elger; David Dr. Henderson


Archive | 1984

11-Beta-aryl-estradienes, their preparation and pharmaceutical compositions containing them

Ralph Rohde; Klaus Annen; Günter Neef; Rudolf Wiechert; Sybille Dr. Beier; Walter Dr Elger; David Dr. Henderson


Archive | 1984

11β-aryl estradienes, processes for their production and pharmaceutical preparations containing them

Guenter Neef; Gerhard Sauer; Rudolf Wiechert; Helmut Hofmeister; Ralph Rohde; Klaus Annen; Henry Laurent; Sybille Beier; Wolfgang Losert; Walter Elger; David Henderson


Archive | 1983

Process for the preparation of 11 beta -hydroxy steroids

Karl Petzoldt; Klaus Annen; Henry Laurent


Synthesis | 1982

A Simple Method for 6-Methylenation of 3-Oxo-Δ4-steroids

Klaus Annen; Helmut Hofmeister; Henry Laurent; Rudolf Wiechert


Archive | 1975

(17)-Alkynyl-(17)-hydroxy-(4,15)-oestradienones and derivs. - progestational agents inhibiting ovulation and implantation

Helmut Hofmeister; Rudolf Wiechert; Klaus Annen; Henry Laurent; Hermann Steinbeck


Archive | 1985

Novel 6,16-dimethylcorticoids their preparation and use

Klaus Annen; Henry Laurent; Helmut Hofmeister; Rudolf Wiechert; Michael Toepert; Hans Wendt

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Henry Laurent

Goethe University Frankfurt

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Helmut Hofmeister

Technical University of Berlin

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Karl Petzoldt

Goethe University Frankfurt

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