Total synthesis and structural confirmation of ent-galbanic acid and marneral.
By capitalizing on a highly selective Claisen rearrangement, ent-galbanic acid 1 and (+)-marneral 2 have been synthesized. The relative configurations of (+)- 1 and (+)- 2 were unambiguously established by X-ray crystallographic analysis of the precursors 11a and 20, with the absolute configuration ensuing from their derivation from R-pulegone. In this way, the controversial issue of the configuration of galbanic acid was unequivocally settled.
Institut de Chimie des Substances Naturelles, CNRS, F-91198 Gif-sur-Yvette, France.
Andrei
A
Corbu
Manuel
M
Perez
Maurizio
M
Aquino
Pascal
P
Retailleau
Simeon
S
Arseniyadis
D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D014315:Triterpenes / Q000138:chemical synthesis* / Q000737:chemistry
D003374:Coumarins; D014315:Triterpenes; C531276:marneral; C048972:galbanic acid