Method for producing optically active cyanohydrin compound

A method of producing an optically active cyanohydrin compound represented by formula (3)

• (wherein, Q1 and Q2 are as defined below, and * represents that the indicated carbon atom is the optically active center) comprising reacting an aldehyde compound represented by formula (2)
• (wherein, Q1 and Q2 represent each independently a hydrogen atom, optionally substituted alkyl group having 1 to 6 carbon atoms, optionally substituted alkoxy group having 1 to 4 carbon atoms, acyloxy group having 2 to 8 carbon atoms, optionally substituted alkanesulfonyloxy group having 1 to 4 carbon atoms, optionally substituted benzenesulfonyloxy group, trialkylsilyloxy group having 1 to 10 carbon atoms or optionally substituted aryloxy group having 6 to 10 carbon atoms) with hydrogen cyanide in the presence of a silyl compound and an asymmetric complex which is obtained by reacting an optically active pyridine compound represented by formula (1)
• (wherein, R1 and R2 represent each independently a hydrogen atom, alkyl group having 1 to 6 carbon atoms, aryl group having 6 to 10 carbon atoms or aralkyl group having 7 to 11 carbon atoms, provided that R1 and R2 are not the same.) with an aluminum halide.