Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
Sontag, B.; Rüth, M.; Spiteller, P.; Arnold, N.; Steglich, W.; Reichert, M.; Bringmann, G.;Chromogenic Meroterpenoids from the Mushrooms Russula ochroleuca and R. viscidaEur. J. Org. Chem.20061023-1033(2006)DOI: 10.1002/ejoc.200500714
The spirodioxolactone ochroleucin A1 (1 ) is responsible for the red colour produced when the stalk base of Russula ochroleuca and R. viscida is treated with aqueous KOH. The labile chromogen rearranges easily into the isomeric dilactoneochroleucin A2 (2 ). Ochroleucin A1 is accompanied by the biosynthetically related hemiacetal ochroleucin B (5 ). The new compounds, whose structures were established by MS and NMR methods, appear to be derived biosynthetically by oxidative condensation of two monomeric units. One of them, 2,5‐dihydroxy‐4‐(3‐methylbut‐3‐en‐1‐ynyl)benzaldehyde (6 ), was detected in the crude toadstool extract by GC/MS comparison with a synthetic sample. The absolute configurations of the ochroleucins A1 and B have been determined by quantum chemical calculation of their CD spectra.
Publikation
Braga, A. L.; Vargas, F.; Sehnem, J. A.; Wessjohann, L. A.;Microwave-Mediated Palladium-Catalyzed Asymmetric Allylic Alkylation Using Chiral β-Seleno AmidesEur. J. Org. Chem.20064993-4997(2006)DOI: 10.1002/ejoc.200600707
A class of enantiopure β‐seleno amide palladium complexes catalyze the microwave‐accelerated enantioselective allylic alkylation of rac ‐1,3‐diphenyl‐2‐propenyl acetate with different malonates. Good yields and enantiomeric excess values of up to 94 % ee were obtained after irradiation times of 2 or 4 min.