Synthesis of optically active 4-substituted 2-cyclohexenones.
Recently, Nicolaou and Baran independently synthesized optically active 4-substituted 2-cyclohexenones via an efficient LiOH-mediated intramolecular aldol condensation. Thus far, application of their cyclization approach has been limited to ketoaldehydes where the R-group is branched. It is demonstrated that the LiOH-mediated cyclization, when applied to substrates containing unbranched R-groups, results in significant erosion of optical purity. A mechanistic justification is provided, and a set of neutral, organocatalyzed conditions is identified that enables cyclization with little loss in optical purity.
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA.
Tania I
TI
Houjeiry
Sarah L
SL
Poe
D Tyler
DT
McQuade
D000447:Aldehydes / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D003512:Cyclohexanones / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D000447:Aldehydes; D003512:Cyclohexanones; D007659:Ketones; C028215:2-cyclohexen-1-one