Stereoselective synthesis of enantiopure β-amino alcohols via nucleophilic β-amino-α-hydroxyalkylation by means of 1-lithiated 2-[N-(diphenylmethyleneamino)]alkyl carbamates

Article abstract of DOI:10.1055/s-1997-1155

2-[N-(Diphenylmethyleneamino)]alkyl carbamates are deprotonated by means of sec-butyllithium in the presence of TMEDA or (-)-sparteine and the diastereomeric ion pairs of α-oxycarbanions formed are substituted by severa1 electrophiles. Deprotection proceeds smoothly to yield chain-elongated β-amino alcohols. Problems arise due to nucleophilic attack of the alkyllithium at one aryl ring of the benzophenone imines under certain reaction conditions.