Syntheses of Optically Active Verrucarinic Acid. 40th Communication on Verrucarins and Roridins
作者:Peter Herold、Peter Mohr、Christoph Tamm
DOI:10.1002/hlca.19830660304
日期:1983.5.5
Three syntheses of (2S, 3R)-2,5-dihydroxy-3-methylpentanoic acid (verrucarinic acid) and its derivatives suitably protected for the further transformation to macrocyclic trichothecenes are described. These involve an enantioselective ester hydrolysis by pig liver esterase, a Sharpless epoxidation and an asymmetric hydroboration.
Synthesis of Verrucarin A and 3?-Hydroxyverrucarin A from Verrucarol and Diacetoxyscripenol (Anguidine). 39th Communication on Verrucarins and Roridins
作者:Peter Mohr、Motoo Tori、Peter Grossen、Peter Herold、Christoph Tamm
DOI:10.1002/hlca.19820650513
日期:1982.7.28
The title compounds have been synthesized starting from verrucarol and diacetoxyscripenol (anguidine), (E, Z)-muconic half ester and a derivative of verrucarinic acid. The latter has been prepared in optically active form from dimethyl 3-methylglutarate.
Synthesis of the Northern Hemisphere of Amphidinolide H2
作者:Markus Kalesse、Florian Liesener、Ulrike Jannsen
DOI:10.1055/s-2006-942459
日期:2006.8
The stereoselective synthesis of the fully functionalized northern hemisphere of the marine natural product amphidinolide H2 is described. A vinylogous Mukaiyama aldol reaction and enzymatic desymmetrization of a meso compound are the key steps in the fragment synthesis. A stereoselective acetate aldol coupling and a 1,3-anti-reduction of the resulting β-hydroxy ketone complete the synthesis of the C14-C26 fragment.
Peptide components of formula 1, pharmaceutically acceptable base salts thereof, pharmaceutical compositions and their use as antiinfective agents ##STR1## where R.sub.1 is alkyl, cycloalkyl or cycloalkylmethyl; R.sub.2 is hydrogen or alkyl and R.sub.3 is hydroxy or an amino acid residu of the formula ##STR2## where X is hydrogen, alkyl or hydroxymethyl and n is an integer of 0 to 4 and R.sub.4 and R.sub.5 are alkyl, hydrogen, benzyl or cyclohexylmethyl.