The [MO-question][1] asks why the classifying space of a group is not necessarily rationally a product of Eilenberg–MacLane spaces. I am looking for classes of examples of connected topological groups/connected associative H-spaces such that their classifying space happens to be rationally a product of Eilenberg–MacLane spaces. I'm the most interested in examples of groups that have an interesting action on a closed manifold. So far I know that this holds for - compact groups, because the cohomology ring of their classifying space is a polynomial ring - Lie groups since they are homotopy equivalent to their maximal compact subgroup - the identity component of the homotopy automorphisms of an aspherical space, because its classifying space is already an Eilenberg–MacLane space. [1]: https://mathoverflow.net/questions/162001/rationalization-of-classifying-spaces "rationalization of classifying spaces"