Rh(I)-catalyzed cyclocarbonylation of allenol esters to prepare acetoxy 4-alkylidenecyclopent-3-en-2-ones.
A Rh(I)-catalyzed cyclocarbonylation reaction of allenol esters has been examined and its synthetic viability established for the conversion of trisubstituted allenes to bicyclo[4.3.0] and -[5.3.0] skeletons possessing an alpha-acetoxy cyclopentadienone. Tetrasubstituted allenol acetates gave elimination products, providing examples of a cyclocarbonylation reaction between an alkyne and a latent cumulene or cumulene equivalent. Cleavage of the acetate affords a free hydroxyl group illustrating the utility of this method for accessing alpha-hydroxy carbonyls from allenol esters.
Brummond
Kay M
KM
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. kbrummon@pitt.edu
Davis
Matthew M
MM
Huang
Chaofeng
C
D002384:Catalysis; D003500:Cyclization; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D004952:Esters; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009281:Naphthalenes / Q000737:chemistry*; D012211:Rhenium / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D003517:Cyclopentanes; D004952:Esters; D007659:Ketones; D009281:Naphthalenes; D012211:Rhenium; C110055:allenolic acid; C013905:cyclopentenone