SYNTHESIS OF BETA-AMINO ESTERS BY THE CONJUGATE ADDITION OF NITROGEN NUCLEOPHILES TO ALPHA,BETA-UNSATURATED ESTERS HAVING CHIRAL P-TOLYLSULFINYL GROUPS

The conjugate addition of nitrogen nucleophiles to t-butyl (E)-2-(p-to lylsulfinyl)cinnamates (1) afforded the corresponding chiral p-amino e aters, which are important building blocks for synthesis of biological ly active polyamine alkaloids. The diastereoselectivity of the reactio ns was 49 to 89%, and (S)-beta-amino esters were obtained from (R)-1 w hile (R)-beta-amino esters were synthesized from (S)-1, respectively.