A chiral or a diastereomeric mixture of 1-[1-(N'N-dimethylaminoethyl)-2-(2'-hydroxyalkylseleno)]-ferrocene (DASF) was easily prepared by the chiral diferrocenyldiselenide (1)and:epoxides. DASF derivatives efficiently catalyzed the ethylation of aldehydes with diethyl zinc to give the secondary alcohols in good to excellent yield with up to 99 % ee.