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of 299
pro vyhledávání: '"Ekkehard Winterfeldt"'
Publikováno v:
ARKIVOC, Vol 2004, Iss 2, Pp 4-23 (2003)
Externí odkaz:
https://doaj.org/article/cffd97dab26e47e0b34663c055c3c34f
Autor:
Ekkehard Winterfeldt
Publikováno v:
CHIMIA, Vol 47, Iss 3 (1993)
In this report we communicate recent results from our investigations with ansa-steroids. Following a detailed inspection of the stereoselectivity of epoxidations, a highly regioselective Baeyer-Villiger oxidation to form lactones was developed. After
Externí odkaz:
https://doaj.org/article/ef70859a4a204453968de126f27c9e1e
Autor:
Ekkehard Winterfeldt
Publikováno v:
Bulletin des Sociétés Chimiques Belges. 97:705-722
Publikováno v:
Bulletin des Sociétés Chimiques Belges. 103:379-387
The alkylated maleic imide adducts of type 3 have been shown to undergo highly regioselective selectride reductions. As with these compounds regioselectivity in further transformations including a thermal retro process translates directly into enanti
Autor:
Tanja Gaich, Ekkehard Winterfeldt
Bringing together examples that until now were often hidden and widely spread throughout the original literature, this textbook shows how to use the correct reagents, conditions or reaction sequences to have access to all possible stereoisomers when
Autor:
Claudia Borm, Ekkehard Winterfeldt
Publikováno v:
Liebigs Annalen. 1996:1209-1212
The kinetic resolution of a malonate-substituted cyclopentenone gave rise to the formation of an enantiopure Diels-Alder adduct which was converted into methyl dehydrocucurbate 2 by diastereoselective alkylation with (Z)-1-bromo-2-pentene and subsequ
Publikováno v:
Angewandte Chemie. 94:496-508
Autor:
Edgar Haak, Ekkehard Winterfeldt
Publikováno v:
Synlett. :1414-1418
The condensation of enaminoketone 8 to α-hydroxyketones gives rise to nonsymmetric pyrazines. This may be of relevance for the biosynthesis of this heterocycle in the cephalostatins and ritterazines.
Publikováno v:
European Journal of Organic Chemistry. 2001:4051-4060
The enolsilyl ether 2, generated from butynone adduct 3, which is easily available from the enantiomerically pure cyclopentadiene 1, proved to be a general building block for polycyclic anellation products to cyclohexenone. After proper adjustment of