EN
For G = SU(n), Sp(n) or Spin(n), let $C_{G}(SU(2))$ be the centralizer of a certain SU(2) in G. We have a natural map $J: G/C_{G}(SU(2)) → Ω₀³G$. For a generator α of $H⁎(G/C_{G}(SU(2));ℤ/2)$, we describe J⁎(α). In particular, it is proved that $J⁎: H⁎(G/C_{G}(SU(2));ℤ/2) → H⁎(Ω₀³G;ℤ/2)$ is injective.