Patent ID: 7291752

Claim:
A process for producing an optically active β-amino acid represented by the formula (I) wherein R1, R2 and R3 are each independently a hydrogen atom, or an optionally substituted alkyl, alkenyl or aryl group, or R1 and R3 may be linked to form a straight chain or branched chain alkylene having 1 to 4 carbon atoms, provided that R1 and R2 are not the same; and * shows an asymmetric carbon, which comprises a step of reacting a compound represented by the formula (II) wherein R1,R2 and R3 are as defined above, and X is an optionally substituted alkoxy, aryloxy, arylalkyloxy or amino group, with a lithium amide represented by the formula (III) wherein R4 and R5 are the same or different and each is a silyl-protecting group, or an optionally substituted benzyl, benzhydryl or trityl group, provided that when one of R4 and R5 is a silyl-protecting group, then the other should be other than a silyl-protecting group, in the presence of a compound represented by the formula (IV) wherein R6, R7, R8 and R9 are the same or different and each is an optionally substituted alkyl group or aryl group, or R6 and R7 may be linked to form a straight chain or branched chain alkylene having 2 to 5 carbon atoms; n is an integer of 0 to 3; and * shows an asymmetric carbon that forms a configuration of (S,S) or (R,R).