Efficient Synthesis of Enantiomerically Pure α-Ionone from (R)- and (S)-α-Damascone

Article abstract of DOI:10.1002/hlca.19920750405

(R)- and (S)-α-ionone ((R)- and (S)-1, resp.) were prepared from (R)- and (S)-α-damascone ((R)- and (S)-3, resp.) without racemization in 48percent yield employing a new enone transposition.The described transposition is complementary to existing methods whose application is often prohibited by the structural requirements of the substrate.The now easily accessible α-ionones of desired absolute configuration are useful as chiral building blocks for terpenoid syntheses.