| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optically active alcohol which is useful as a medicine, agrochemical or the like in high asymmetric yield by asymmetric reduction of an unsymmetrical ketone with hydroborane in the presence of a chiralβ- aminoalcohol and a trialkoxyborane. SOLUTION: (A) A compound formula I (R<1> and R<2> are each an organic residue different from each other) is reduced with (D) hydroborane in the presence of (B) a chiralβ-aminoalcohol of formula II [R<3> is an alkyl, a cycloalkyl, a (substituted) aryl; R<4> and R<5> are each H, an alkyl; R<6> is H, an alkyl, a cycloalkyl; * is an asymmetric carbon] and (C) a compound of formula III (R<7> is an alkyl) to give an optically active alcohol of formula IV (R<1> ' and R<2> ' are each an organic residue same as R<1> and R<2> respectively). The component A is preferably, for example, acetophenone, propiophenone, phenacyl chloride, benzyl phenyl ketone. Anα-oxoketoxime derivative also may be used as a component A.
|
