Highly enantioselective proton-initiated polycyclization of polyenes.
This report describes the synthesis of a range of chiral polycyclic molecules (tricyclic to pentacyclic) from achiral polyene precursors by enantioselective proton-initiated polycyclization promoted by the 1:1 complex of o,o'-dichloro-BINOL and SbCl(5). Excellent yields (ca. 90% per ring formed) and enantioselectivety (20:1 to 50:1) were obtained. The process is practical as well as efficient, because the chiral ligand is both readily prepared from R,R- or S,S-BINOL and easily recovered from the reaction mixture by extraction.
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Karavadhi
K
Surendra
E J
EJ
Corey
D000965:Antimony / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D009284:Naphthols / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000138:chemical synthesis* / Q000737:chemistry; D011090:Polyenes / Q000737:chemistry*; D011522:Protons; D013237:Stereoisomerism
C406944:BINOL, naphthol; D009284:Naphthols; D011084:Polycyclic Aromatic Hydrocarbons; D011090:Polyenes; D011522:Protons; D000965:Antimony