Regioselective single and double conjugate additions to substituted cyclohexa-2,5-dienone monoacetals.
[reaction: see text]. A series of quinone monoacetals bearing electron-withdrawing groups was treated with diethyl malonate and other bifunctional nucleophiles in the presence of KO-t-Bu in THF. Reactions of ethyl 3-nitropropionate or diethyl malonate resulted in single conjugate addition adducts. When ethyl acetoacetate was used as a nucleophile, bridged bicyclic products were obtained in good yields. The regiochemistry of conjugate addition was dependent on the quinone monoacetal substitution.
Grecian
Scott
S
Department of Medicinal Chemistry, Room 4070, Malott Hall, University of Kansas, Lawrence, 66045-7582, USA.
Wrobleski
Aaron D
AD
Aubé
Jeffrey
J
D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis*; D018360:Crystallography, X-Ray; D003510:Cyclohexanes / Q000737:chemistry*; D053138:Cyclohexenes; D008968:Molecular Conformation; D015394:Molecular Structure; D013237:Stereoisomerism
D019086:Bridged Bicyclo Compounds, Heterocyclic; D003510:Cyclohexanes; D053138:Cyclohexenes; C507608:cyclohexadienone