ausblenden:
Schlagwörter:
DIELS-ALDER REACTIONS; DIETHYLZINC; ESTERS
Zusammenfassung:
Enantiomerically pure C-2-symmetric 1,4-diols embodying bicyclic C-frameworks were synthesized by means of asymmetric carbo-Diels-Alder reactions as key steps (Scheme 1). They were investigated as chiral ligands in the enantioselective addition of ZnEt(2) to aromatic aldehydes. In the presence of 20-40 mol-% of the titanates formed from these diols and [Ti(i-PrO)(4)] at -78 degrees, the respective 1-arylpropanols were obtained with enantiomer ratios up to 93:7(Scheme 2, Table).