The organocatalyzed domino Michael–aldol reaction revisited. Synthesis of enantioenriched 3-hydroxycyclohexanone derivatives by reaction of enals with α,α′-diaryl-substituted acetone

摘要: The reaction of enals with α,α′-diaryl-substituted acetones (pKa > 18) catalyzed by (S)-1-(2-pyrrolidinylmethyl) pyrrolidine provides direct access to enantioenriched 2,5,6-trisubstituted-3-hydroxy cyclohexanones. process constitutes a highly stereoselective organocatalytic tandem Michael-intramolecular aldol reaction. It has been demonstrated that the stereoselection is dependent on conditions because only syn diastereoisomers are able cyclize, and anti participate in retro-Michael decreasing enantioselection.