Remarkable phosphine-effect on the intramolecular aldol reactions of unsaturated 1,5-diketones: highly regioselective synthesis of cross-conjugated dienones.
We report a phosphine-mediated intramolecular aldol cyclization of unsaturated diketones that proceeds with extremely high levels of regioselectivity for the cross-conjugated bicyclic dienone products. The sense of regioselectivity observed in this reaction is complementary to that obtained using traditional aldol conditions. Experimental evidence that supports the involvement of a phosphine Michael adduct is described.
Thalji
Reema K
RK
Department of Chemistry, University of Michigan, Ann Arbor, 48109, USA.
Roush
William R
WR
D000475:Alkenes / Q000737:chemistry*; D003500:Cyclization; D003516:Cycloparaffins / Q000138:chemical synthesis*; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry*; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000138:chemical synthesis / Q000737:chemistry
D000475:Alkenes; D003516:Cycloparaffins; D007659:Ketones; D010720:Phosphines; D014753:Vinyl Compounds