gcj (GNU Compiler for Java) can compile JVM class files to machine code.
Technically, the JVM also compiles your Clojure to the native instruction set, via JIT; but I don't think a JIT compiler performs the same level of optimizations (due to time constraints) as a say "gcc -O3".
Of course the big advantage of easy availability of all those Java libraries will be gone. But it might open other doors.