The present invention relates to the reduction of polycyano compounds to produce polyamines, in particular diaminoacetal and diaminoketal compounds, and their use as curing agents in epoxy resin compositions. The reduction with molecular hydrogen can be carried out using a metal catalyst selected from GROUP VIII and a catalytic promoter. The reduction can include anhydrous or aqueous ammonia. The reaction can be carried out in continuous and batch modes with catalyst and solvent recycling. The epoxy resin composition consisting of an epoxy resin and a polyamine curing agent that can be used in fiber-reinforced composite materials, coating materials, and the like.