On the verge of axial chirality: atroposelective synthesis of the AB-biaryl fragment of vancomycin.
[structure: see text] Using the "lactone concept", differently substituted AB-biaryl fragments (P)-2 (R = Me, t-Bu) of vancomycin have been synthesized atroposelectively. Their otherwise configurational instability was remedied by inclusion of two chlorine atoms in the B ring to give (M)-29. Starting from a still configurationally unstable lactone-bridged precursor, we obtained this biaryl with high atroposelectivity (dr 94:6) by ring cleavage with dynamic kinetic diastereomeric resolution.
Institut für Organische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany. bringman@chemie.uni-wuerzburg.de
Gerhard
G
Bringmann
Dirk
D
Menche
Jörg
J
Mühlbacher
Matthias
M
Reichert
Nozomi
N
Saito
Steven S
SS
Pfeiffer
Bruce H
BH
Lipshutz
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis*; D002713:Chlorine; D007783:Lactones / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D014640:Vancomycin / Q000138:chemical synthesis*
D000900:Anti-Bacterial Agents; D007783:Lactones; D002713:Chlorine; D014640:Vancomycin