After fiddling around with rpmbuild for quite a while, I stumbled upon yum-builddep. It’s basically a tool to install all packages required to rebuild an RPM package from the SRPM. So if you want to install all “BuildRequires” mentioned in the spec file of a package, invoke

yum-builddep <package name>

The source RPM for the specified package must be available in the yum repository or it can be a local source RPM file.

yum-builddep itself it part of the yum-utils package. You can install it with yum

yum install yum-utils

See also yum-builddep manpage