2003 Alcohols

AlcoholsQ 0230 Novel Preparation of Non-Racemic 1-[α-(1-Azacycloalkyl)benzyl]-2-naphthols

from Betti Base and Their Application as Chiral Ligands in the Asymmetric Addition of Diethylzinc to Aryl Aldehydes. — Six chiral cyclic aminophenol ligands are prepared by selective N-cyclizations of Betti bases with dials in the presence of NaBH3CN to give 1-azacycloalka[2,1-b] oxazines followed by selective cleavage of C—O bonds. The size of the azacycloalkane in the chiral ligands has essential influence on their induced asymmetric additions. Ligands incorporating a pyrrolidine or piperi-dine ring furnish products in excellent yields and enantiomeric purity, whereas azepanes, cf. (Ic) afford products in moderate optical yield. — (LU, J.; XU, X.; WANG, S.; WANG, C.; HU*, Y.; HU, H.; J. Chem. Soc., Perkin Trans. 1 2002, 24, 2900-2903; Dep. Chem., Nanjing Univ., Nanjing 210093, Peop. Rep. China; Eng.) — H. Hoennerscheid

20- 092