Concise synthesis of (S,S)-(+)-dehydrohomoancepsenolide.
A concise total synthesis of the bis-butenolide 3 in optically active form is reported. Key steps are a zinc-mediated "three-component coupling" with formation of dienyne 9 which undergoes ring closing metathesis (RCM) on treatment with (PCy(3))(2)Cl(2)Ru=CHPh. Dimerization of the resulting butenolide 11 is then achieved via alkyne metathesis using (tBuO)(3)W&tbd1;CCMe(3) as the catalyst. A Lindlar reduction completes this synthesis which delivers product 3 in only five steps with an overall yield of 25%.
Fürstner
A
A
Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany. fuerstner@mpi-muelheim.mpg.de
Dierkes
T
T
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D007202:Indicators and Reagents; D008958:Models, Molecular; D008968:Molecular Conformation
D007202:Indicators and Reagents; C413202:dehydrohomoancepsenolide; D015107:4-Butyrolactone