Synthesis of cyclopentenones via intramolecular HWE and the palladium-catalyzed reactions of allylic hydroxy phosphonate derivatives.
Palladium-catalyzed decarboxylative rearrangement of nonracemic phosphono allylic acetoacetates, or the intermolecular allylic substitution of nonracemic phosphono allylic carbonates with tert-butyl acetoacetate followed by hydrolysis and decarboxylation, gave omega-ketovinyl phosphonates. A highly regioselective Wacker oxidation gave the omega,beta-diketophosphonates which underwent intramolecular HWE reaction to give nonracemic cyclopentenones. An aldol condensation leading to phosphonocyclopentenones was competitive with the HWE reaction. The stereochemistry of the cyclopentenone and the ratio of HWE to aldol products were dependent upon the choice of base used in the reaction.
Department of Chemistry and Biochemistry, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri 63121-4499, USA.
Bingli
B
Yan
Christopher D
CD
Spilling
D000090:Acetoacetates / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D000498:Allyl Compounds / Q000737:chemistry*; D002384:Catalysis; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D006900:Hydroxylation; D015394:Molecular Structure; D063065:Organophosphonates / Q000737:chemistry*; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism; D014753:Vinyl Compounds / Q000737:chemistry
D000090:Acetoacetates; D000447:Aldehydes; D000498:Allyl Compounds; D003517:Cyclopentanes; D063065:Organophosphonates; D014753:Vinyl Compounds; C016635:acetoacetic acid; D010165:Palladium; C116609:3-hydroxybutanal; C013905:cyclopentenone