Abstract
A series of optically active 1,4-aminoalcohols were synthesized from the corresponding lactones, which were prepared from (+)-camphor and (-)-fenchone, via hydroxy amides. The addition reactions of diethylzinc to aldehydes using the 1,4-aminoalcohols as chiral catalysts were investigated. 1,4-Aminoalcohol catalysts derived from (+)-camphor resulted in secondary (S)-alcohols as the major product.
The 1,4-aminoalcohols bearing two propyl groups achieved the highest enantioselectivity; the enantiomeric excess was 95%. 1,4-Aminoalcohol catalysts derived from (-)-fencone resulted in secondary (R)-alcohols as the major product. In the chiral 1,4-aminoalcohols from (-)-fencone, the alcohol containing a morpholine structure appended to the amino group possessed the highest enantioselectivity; with an enantiomeric excess of 79%.
