45 research outputs found
Aldosterone Glucuronide, an Important Biomarker: Synthesis and Structure Elucidation of Novel Isomers
No full textEnantioselective Total Synthesis of Chromanone Lactone Homo‐ and Heterodimers
No full textAbstract A one pot borylation/Suzuki–Miyaura reaction of the 4‐bromochromanone lactones 21 and 23 , respectively, followed by cleavage of the methyl ether moieties gave the homodimeric chromanone lactones 10 and 11 . Reaction of a 1:1 mixture of 21 and 23 under otherwise identical conditions gave a 1:1:2‐mixture of the two homodimers 10 and 11 and the heterodimer 12 . This is the first example of the preparation of a heterodimeric chromanone lactone. For the enantioselective synthesis of the starting material, phenol 17 was transformed into the chromane 18 using a Wacker‐type cyclisation with 99 % ee and 80 % yield
Enantioselective Total Synthesis of Blennolide H and Phomopsis-H76 A and Determination of Their Structure
No full textAbstract This work reports on the enantioselective total synthesis of the two dimeric natural chromanone lactones phomopsis‐H76 A ( 5 ) and blennolide H ( 6 ). Both syntheses could be achieved from chromane 11, which was obtained by an enantioselective Wacker‐type cyclization with >99 % ee . The dimerization of the corresponding monomers was performed using a palladium‐catalyzed Suzuki reaction. Moreover, within this work it was possible to revise the absolute configuration of phomopsis‐H76 A and determine the relative as well as absolute configuration of blennolide H
Enantioselective Total Synthesis of the Fungal Metabolite Blennolide D and the Enantiomers of Blennolide E and F
No full textEnantioselective Total Synthesis and Structure Confirmation of the Natural Dimeric Tetrahydroxanthenone Dicerandrol C
No full textThe first enantioselective total synthesis of natural dicerandrol C (1c) as its enantiomer containing a dimeric tetrahydroxanthenone skeleton is described starting from the enantiopure chromane 6 which was obtained through a Wacker-type cyclization with >99%ee. For the formation of the dimeric skeleton a palladium-catalyzed Suzuki reaction was used. The synthesis allowed the confirmation of the absolute configuration of the dicerandrols
ChemInform Abstract: Benzylidene Acetal Protecting Group as Carboxylic Acid Surrogate: Synthesis of Functionalized Uronic Acids and Sugar Amino Acids.
No full textBenzylidene Acetal Protecting Group as Carboxylic Acid Surrogate: Synthesis of Functionalized Uronic Acids and Sugar Amino Acids
No full text‐Alkynylglycosides: Facile Synthesis of Polyhydroxy Tetrahydroindolizines
No full textA mild and efficient one-pot method has been developed for the stereoselective synthesis of structurally diverse novel iminosugar C-alkynylglycosides (see scheme). The generality of this methodology has been demonstrated with a wide variety of amines and copper acetylides. This one-pot method has been exploited in the synthesis of a new class of DNA cross-linking agents, polyhydroxy 1-vinyl-tetrahydroindolizine derivatives
