SYNTHESIS AND APPLICATION OF NEW (THREO)-AMINO AND (ERYTHRO)-AMINO ALCOHOLS BASED ON THE OCTAHYDRO-CYCLOPENTA[B]PYRROLE SYSTEM IN THE CATALYTIC ENANTIOSELECTIVE ADDITION OF DIETHYLZINC TO BENZALDEHYDE

Asymmetric catalytic ethylation of benzaldehyde utilizing a series of new, artificial B-amino alcohols based on the octahydro-cyclopenta[b]p yrrole system is presented. A systematic investigation on the inductiv e correlation of up to four catalyst-internal stereogenic centers and on steric aspects of these structures has been conducted with diastere omerically pure, bicyclic (erythro)- and (threo)-compounds 2-13. Chira l ligands have been developed reaching excellent enantioselectivities, e.g. enantiomeric excesses up to 91% with a favored (R)-induction. (C ) 1997 Elsevier Science Ltd.