1993 年 51 巻 7 号 p. 620-630
A wide variety of bicyclic amino alcohols have been prepared from D-camphor and screened as chiral elements in asymmetric synthesis. Endo-3-amino-endo-2-hydroxybornane and exo-3-amino-exo-2-hydroxybornane were found to be efficient chiral auxiliaries for the synthesis of optically pure cyclopropane derivatives, and [P]- and [M]- heterohelicenes. Both (S)- and (R)-secondary alcohols are obtained with predictable stereochemistry by utilizing these diastereomeric amino alcohols as catalysts in the addition of diethylzinc to aldehydes and in reduction of aromatic ketones by borane. The shortest asymmetric synthesis of (R)-(-)-muscone with essentially 100% enantiomeric excess (ee) was accomplished by employing (1R, 2R, 3S, 4S)-3-[(1-methyl-2-pyrrolyl)methylamino]-1, 7, 7-trimethylbicylo[2.2.1]heptan-2-ol as a non-transferable ligand in the conjugate addition of alkoxydimethylcuprate to (E)-2-cyclopentadecenone. This asymmetric conjugate addition was promoted by use of 0.36 equivalents of the amino alcohol as a chiral catalyst, giving (R)-muscone in 99% ee and 86% chemical yield.