EFFECTIVE ENANTIOCONTROL IN CONJUGATE ADDITIONS OF ORGANOCUPRATES - HIGHLY SELECTIVE 1,5-CHIRAL INDUCTION IN THE CONJUGATE ADDITIONS OF CUPRATES TO OR ALPHA,BETA-UNSATURATED AMIDE DERIVATIVES OF 2,2-DIMETHYLOXAZOLIDINE CHIRAL AUXILIARIES

alpha,beta-Unsaturated amide derivatives of 2,2-dimethyloxazolidines, developed as new chirality-controlling auxiliaries based on the restri cted rotation of the amide linkage, have been applied to the enantioco ntrol of conjugate additions of lithium and magnesium cuprates. High s electivities of 1,5-chiral inductions are attained, indicating their p romising synthetic potential in asymmetric synthesis. The diastereofac ial selectivities depend upon the efficiency of steric shielding by th e 4-substituent of the chiral auxiliary, and the reaction of -3-[(E)-2 -butenoyl]-2,2,5,5-tetramethyloxazolidine with Ph(2)CuMgBr.MgBrI is ex clusively lk-1,5-inductive. Use of organolithium and organomagnesium s how opposite low selectivities. It is concluded that the stereochemist ry of cuprate conjugate addition is determined at the step of formatio n of the d,pi type charge transfer complexes.