Zobrazeno 1 - 10
of 17
pro vyhledávání: '"Ralf Gerke"'
Publikováno v:
Tetrahedron. 65:1689-1696
A combination of three spiroannelation methods forms the basis for a synthesis of the first two helical hydrocarbons of 1,3-spiroannelated five-membered rings.
Publikováno v:
Tetrahedron. 65:1040-1047
New approaches to the protoilludane sesquiterpenes (±)-cerapicol and (±)-sterpurene via rearrangement routes are described. The absolute configuration of (+)-cerapicol has been determined and found in accord with a biosynthesis of the natural produ
Publikováno v:
Tetrahedron. 60:1205-1213
A new approach to helical primary structures of four-membered rings uses a cycloaddition of a trimethylenketeniminium salt to suitable tailored methylenecyclobutanes to assemble the desired carbon framework. The results are short and effective synthe
Publikováno v:
Tetrahedron. 59:4443-4449
The synthesis of (M)-trispiro[3.0.0.3.2.2]tridecane [ (M)-4 ], the first hydrocarbon with a helical primary structure of four-membered rings, is described. Key step is the kinetic resolution of a cyclobutanone through reduction with bakers' yeast. As
Publikováno v:
Tetrahedron. 55:14429-14434
Oxidative dimerization of a mixture of the thiolanone 5 and the dithiolanone 4 yields 2c as chromophore of thioindigo 1c, and 6 and 7 as chromophores of still unknown indigo dyes. As compared to 2c, the first ionization potential of the new indigo ch
Publikováno v:
Tetrahedron. 55:14421-14428
The base catalyzed N,N′-dialkylation of the vinylogous indigo dye cis-cis-2a proceeds with concomitant isomerization and yields cis-trans-2b,c as minor, and trans-trans-2b,c,d as major products. Upon exposure to light, cis-trans-2b,c isomerizes to
Publikováno v:
Tetrahedron. 55:6119-6128
The synthesis and rearrangement of the cyclobutyl methanol 4 is described. The synthesis has been achieved by addition of the Grignard reagent 16 to the bicyclic ketone 22 . Experimental procedures for the preparation of both compounds are given. Upo
Autor:
Uta Kaiser, O. Graalmann, Mathias Noltemeyer, Heike Schröder, Thorsten Anger, Lutz Fitjer, Ralf Gerke
Publikováno v:
Tetrahedron. 54:10713-10720
The bicyclobutylidenes 2 and 5 have been rearranged to the bicyclooctenes 3 and 6, respectively, and further transformed to the tricyclic ketones 16 and 21, respectively, as known precursors of (±)-ceratopicanol (4) and (±)-hirsutene (7). For the c
Autor:
Mathias Noltemeyer, Lutz Fitjer, Andreas Malich, Sabine Kluge, Joerg Weiser, Beate Rissom, Carola Paschke, Ralf Gerke
Publikováno v:
Journal of the American Chemical Society. 117:9180-9189
Publikováno v:
ChemInform. 26