Abstract. In this paper, we show that for a Koszul n-homogeneous algebra Λ, the quadratic dual of certain twisted trivial extension is the (n + 1)-preprojective algebra of its quadratic dual, that is, (∆νΛ)!,op ≃ Π(Λ!,op).This is applied to the τ-slice algebras of stable n-translation algebras andgives a noncommutative version of Bernstein-Gelfand-Gelfand correspondencefor such algebras.